We are not equally empathic

 

The Child at Your Door (c. 1917-1919). We're not equally empathic toward strangers. This largely heritable trait varies continuously from psychopathy to extraordinary altruism (source: Wikicommons)

 

In a previous post, I discussed why the capacity for affective empathy varies not only between individuals but also between populations. First, its heritability is high: 68% (Chakrabarti and Baron-Cohen, 2013). So natural selection has had something to grab hold of. Second, its usefulness varies from one culture to another. It matters less where kinship matters more, i.e., where people interact mainly with close kin and where non-kin are likely to be enemies. The threat of retaliation from kin is sufficient to ensure correct behavior.

Affective empathy matters more where kinship matters less. This is a situation that Northwest Europeans have long known. Historian Alan Macfarlane argues that kinship has been weaker among the English—and individualism correspondingly stronger—since at least the 12th century and perhaps since Anglo-Saxon times (Macfarlane, 2012; Macfarlane, 1992, pp. 173-174). A weaker sense of kinship seems to underlie the Western European Marriage Pattern (WEMP), as seen by its defining characteristics: late age of marriage for both sexes; high rate of celibacy; strong tendency of children to form new households; and high circulation of non-kin among families. The WEMP has prevailed since at least the 12th century west of the Hajnal Line, a line running approximately from Trieste to St. Petersburg (Hallam, 1985; Seccombe, 1992, p. 94).

Can natural selection specifically target affective empathy?

So if affective empathy helps people to survive and reproduce, there will be more and more of it in succeeding generations. If not, there will be less and less.

But what exactly is being passed on or not passed on? A specific capacity? Or something more general, like pro-social behavior? If it's too general, natural selection could not easily make some populations more altruistic than others. There would be too many nasty side-effects.

Although pro-social behavior superficially looks like affective empathy, the underlying mental processes are different. Pro-social behavior is a willingness to help others through low-cost assistance: advice, conversation, a helping hand, etc. The logic is simple: give some help now and perhaps you'll receive a lot later from the grateful beneficiary. By the same logic, you may stop helping someone who seldom reciprocates.

Affective empathy is less conscious. It seems to have developed out of cognitive empathy: the ability to simulate what is going on in other people's minds, but not necessarily for the purpose of helping them. Con artists have plenty of cognitive empathy. Empathy is affective when you not only simulate how other people feel but also experience their feelings (Chakrabarti and Baron-Cohen,2013). Their wellbeing comes to matter as much as your own.

 

Empathy of either sort relies on unconscious mimicry: "empathic individuals exhibit nonconscious mimicry of the postures, mannerisms, and facial expressions of others (the chameleon effect) to a greater extent than nonempathic individuals" (Carr et al., 2003). The ability to mimic is key to the empathic process of relaying information from one brain area to another via "mirror neurons":

- The superior temporal cortex codes an early visual description of another person's action and sends this information to posterior parietal mirror neurons.

- The posterior parietal cortex codes the precise kinesthetic aspect of the action and sends the information to inferior frontal mirror neurons.

- The inferior frontal cortex codes the purpose of the action.

- Parietal and frontal mirror areas send copies of motor plans back to the superior temporal cortex in order to match the visual description of the person's action to the predicted sensory consequences for that person.

- The mental simulation is complete when the visual description has been matched to the predicted sensory consequences (Carr et al., 2003).

By simulating the sensory consequences of what someone does or intends to do, we gain an understanding of that person that goes beyond what our senses immediately tell us.

 

[...] we understand the feelings of others via a mechanism of action representation shaping emotional content, such that we ground our empathic resonance in the experience of our acting body and the emotions associated with specific movements. As Lipps noted, ''When I observe a circus performer on a hanging wire, I feel I am inside him.'' To empathize, we need to invoke the representation of the actions associated with the emotions we are witnessing. (Carr et al., 2003)

Affective empathy exists when this mental representation is fed into our own emotional state. We feel what the other person feels and we act appropriately. This is much more than pro-social behavior.

From psychopaths to extraordinary altruists

The capacity for affective empathy varies from one person to the next. It is least developed in psychopaths:

Psychopathy is a heritable developmental disorder characterized by an uncaring nature, antisocial and aggressive behavior, and deficient prosocial emotions such as empathy, guilt, and remorse. Psychopaths exhibit consistent patterns of neuroanatomical and functional impairments, such as reductions in the volume of the amygdala and in the responsiveness of this structure to fear-relevant stimuli. These deficits may underlie the perceptual insensitivity to fearful facial expressions and other fear-relevant stimuli observed in this population. (Marsh et al., 2014)

Mainstream opinion accepts that psychopaths are heritably different because they are "sick." Heritable differences are thus thought to be unusual and even pathological. "Normal" individuals may vary in their capacity for affective empathy, but surely that sort of variability is due to their environment, isn't it?

No it isn't. That variability, too, is largely genetic. Affective empathy varies over a largely heritable continuum, and an arbitrary line is all that separates psychopaths from "normal" individuals. There may be many psychopaths or there may be few; it depends on where you set the cut-off point.

At the other end of this continuum is another interesting group: extraordinary altruists. A research team has recently looked at the brains of such people, specifically individuals who had donated one of their kidneys to a stranger:

Given emerging consensus that psychopathy is a continuously distributed variable within the general population and that psychopaths represent one extreme end of a caring continuum, we hypothesized that extraordinary altruism may represent the opposite end of this continuum and be supported by neural and cognitive mechanisms that represent the inverse of psychopathy; in particular, increased amygdala volume and responsiveness to fearful facial expressions. (Marsh etal., 2014)

In extraordinary altruists, the right amygdala is larger and responds more to fearful facial expressions. This is the inverse of what we see in psychopaths, who have smaller amygdala and are less responsive to fearful facial expressions.

Affective empathy is thus a specific mental trait, like psychopathy. It is not a form of pro-social behavior any more than psychopathy is a form of antisociality:

[...] it is important to distinguish between antisociality that results from psychopathy, which is specifically associated with reduced empathy and concern for others, as well as with reduced sensitivity to others' fear and distress, and antisociality that results from any of a variety of other factors, such as impulsivity or trauma exposure, that are not closely related to empathy. (Marshet al., 2014)

Marsh et al. (2014) cite a number of studies to show the relative independence of these two behavioral axes: prosociality / antisociality and affective empathy / psychopathy.

Conclusion

Affective empathy is specific and largely heritable. People differ continuously in their innate capacity for affective empathy, and it is only by setting an arbitrary cut-off point that we classify some as "psychopaths" and others as "normal," including extraordinary altruists who may be a small minority.

Affective empathy is an intricate adaptation that must have evolved for some reason. Initially, it may have served to facilitate the relationship between a mother and her children, this being perhaps why it is stronger in women than in men (Baron-Cohen and Wheelwright, 2004). In some cultures, natural selection may have increased this capacity in both sexes and extended it to a wider range of social interactions. This scenario would especially apply to Northwest Europeans, who have long had relatively weak kinship. They have consequently relied more on internal means of behavior control, like affective empathy (Frost, 2014).

 

References

 

Baron-Cohen, S. and S. Wheelwright. (2004).The Empathy Quotient: An investigation of adults with Asperger Syndrome or high functioning autism, and normal sex differences. Journal of Autism and Developmental Disorders, 34, 163-175.

http://ftp.aspires-relationships.com/the_empathy_quotion_of_adults_with_as.pdf

 

Carr, L., M. Iacoboni, M-C. Dubeau, J.C. Mazziotta, and G.L. Lenzi. (2003). Neural mechanisms of empathy in humans: A relay from neural systems for imitation to limbic areas, Proceedings of the National Academy of Sciences (USA), 100, 5497-5502.

http://www.ucp.pt/site/resources/documents/ICS/GNC/ArtigosGNC/AlexandreCastroCaldas/7_CaIaDuMaLe03.pdf

 

Chakrabarti, B. and S. Baron-Cohen. (2013). Understanding the genetics of empathy and the autistic spectrum, in S. Baron-Cohen, H. Tager-Flusberg, M. Lombardo. (eds). Understanding Other Minds: Perspectives from Developmental Social Neuroscience, Oxford: Oxford University Press.

http://books.google.ca/books?hl=fr&lr=&id=eTdLAAAAQBAJ&oi=fnd&pg=PA326&ots=fHpygaxaMQ&sig=_sJsVgdoe0hc-fFbzaW3GMEslZU#v=onepage&q&f=false

 

Frost, P. (2014). Affective empathy. An evolutionary mistake?  Evo and Proud, September 20

http://evoandproud.blogspot.ca/2014/09/affective-empathy-evolutionary-mistake.html

Hallam, H.E. (1985). Age at first marriage and age at death in the Lincolnshire Fenland, 1252-1478, Population Studies, 39, 55-69.

 

Macfarlane, A. (1992). On individualism, Proceedings of the British Academy, 82, 171-199.

http://www.alanmacfarlane.com/TEXTS/On_Individualism.pdf

 

Macfarlane, A. (2012). The invention of the modern world. Chapter 8: Family, friendship and population, The Fortnightly Review, Spring-Summer serial

http://fortnightlyreview.co.uk/2012/07/invention-8/

 

Marsh, A.A., S.A. Stoycos, K.M. Brethel-Haurwitz, P. Robinson, J.W. VanMeter, and E.M. Cardinale. (2014). Neural and cognitive characteristics of extraordinary altruists, Proceedings of the National Academy of Sciences, 111, 15036-15041.

http://www.pnas.org/content/111/42/15036.short

Seccombe, W. (1992). A Millennium of Family Change. Feudalism to Capitalism in Northwestern Europe, London: Verso.

Affective empathy, an evolutionary mistake?

 

The Classic of Filial Piety, Ma Hezhi, 12^th century (Wikicommons). In China, empathy is experienced primarily as a moral duty, rather than as an involuntary emotional response.

 

In a previous post, I asked, "How universal is empathy?" The question is tricky because empathy has three components:

1. pro-social behavior - willingness to help people out, hospitality to strangers, acts of compassion.

2. cognitive empathy - capacity to see things from another person's perspective and to understand how he or she feels.

3. affective or emotional empathy - capacity not only to understand how another person feels but also to experience those feelings involuntarily and to respond appropriately. Failure to help a person in distress can trigger a self-destructive sequence: anguish, depression, suicidal ideation.

Pro-social behavior is very widespread among humans and may even be universal. It isn't unconditional, however. It can be used strategically and is often influenced by previous experiences with the person in question.

Cognitive empathy seems much less universal. In Oceanic cultures, for instance, there is both an unwillingness and an inability to know what other people feel. A person's inner feelings are said to be private and unknowable (Lepowski, 2011).

Affective empathy has an even more restricted range. If the range of empathic guilt is indicative, it may reach its highest incidences in the "guilt cultures" of northwestern Europe. In these cultures, guilt outweighs shame as a way to enforce social rules. What's the difference between the two? You feel shame when someone from your community sees you breaking a rule. With guilt, no witnesses are needed. You feel guilty when no else is watching or even when you merely think of breaking the rule.

Until recently, empathy has been studied only in Western populations, with the result that it is often assumed to have the same characteristics everywhere, at least potentially. This shortcoming was noted in a Hong Kong study: "A limitation of the existing literature on empathy in the social work context is that most of the existing studies on empathy are Western studies, and there are very few empirical studies of empathy in Chinese populations" (Siu and Shek, 2005)

When Siu and Shek (2005) studied empathy in a Chinese sample ranging from 18 to 29 years of age, they found that the participants made little distinction between cognitive empathy and affective (emotional) empathy. These two components seemed to be weakly differentiated from each other. The authors attributed this finding to "cultural differences" "Chinese people might not perceive the items from the two dimensions as too different in nature." The authors went on to note that "there are still debates concerning the boundaries of emotional and cognitive processes underlying empathy" and that "the causal relationships between cognitive and emotional processing underlying empathy are not simple or unidirectional."

In short, the Chinese participants could see things from another person's perspective and understand how that person felt. There is much less indication, however, that they involuntarily experienced the feelings of other people, especially feelings of distress. This is not to say they were incapable of such emotion transference, but rather that it seems limited in scope, perhaps being confined to family members and not extended to strangers.

In general, empathy is perceived in China as a moral duty and not as an involuntary emotional response. The authors underline this point when they discuss relevant beliefs in their culture:

These include the cultural beliefs of "qi suo bu yu, wu shi yu ren" (do not do unto others that you would not wish others to do on you), "jiang xin bi ji" (compare people's hearts with your own), "she shen chu di" (put yourself into other people's position), and "shen tong gan shou" (experiencing the experience of other people). With the emphases on collectivism and familism (Yang, 1981), taking the views of others is an essential duty, and the lack of consideration to others' perspectives is generally regarded as a lack of virtue in the Chinese culture (Wong, 1998). (Siu and Shek, 2005)

 

From cognitive empathy to affective empathy: the how and why

In humans, empathy seems to have differentiated progressively into its three components, with pro-social behavior being the oldest and most widespread one, followed by cognitive empathy and, finally, affective empathy.

 

This kind of mental evolution has been certainly possible in our species:

First, all three components display moderate to high heritability, especially the last one, i.e., 68% (Chakrabarti and Baron-Cohen, 2013). There has thus been a potential for gene-culture co-evolution.

Second, gene-culture co-evolution seems to have been widespread. About 10,000 years ago, human genetic evolution accelerated by over a hundred-fold, yet by that time our ancestors had colonized this planet from the tropics to the arctic (Hawks et al., 2007). They were evolving primarily in response to different cultural environments, and only secondarily to different physical environments.

Third, people have thus been selected for their ability to function in a certain cultural environment, just as they have been selected for their ability to function in heat or cold.

That answers the "how" question, but what about the "why"? Why was affective empathy more advantageous at the northwestern end of Eurasia? Together with empathic guilt, it may be part of a larger behavioral adaptation called the Western European Marriage Pattern, which seems to reflect a culture where kinship ties are relatively weak and thus insufficient to enforce rules of correct behavior.

The WEMP predominates north and west of an imaginary line running from Trieste to St. Petersburg and has the following general characteristics:

 - men and women tend to marry relatively late and many never marry

- children usually leave the family to form new households

- a high proportion of non-kin circulate among different households (Hajnal, 1965)

This zone of relatively weak kinship existed before the Black Death of the 14th century and is attested by fragmentary evidence going back to the 9th century and even earlier (Hallam, 1985; Seccombe, 1992, p. 94). I suspect its origins go back to a unique Mesolithic culture that once existed along the North Sea and the Baltic (Price, 1991). At that time, an abundance of marine resources drew people to the coast each year for fishing, sealing, and shellfish collecting, thus creating large but fluid settlements unlike anything seen in other hunter-gatherers. Social interactions would have largely involved non-kin, and there would have thus been strong selection for mechanisms that could enforce social rules in the absence of kin obligations.

 

Conclusion

Through their high capacity for affective empathy and empathic guilt, these Northwest Europeans had an edge in adapting to later cultural environments that would be structured not by kinship but by other ways of organizing social relations: the State, ideology, and the market economy.

This has been one path that leads to advanced societies, but it is not the only one. East Asian societies have pursued a similar path of cultural evolution while having relatively low levels of affective empathy and empathic guilt. They seem to have done so by relying more on external means of behavior control (shaming, family discipline, community surveillance) and by building on cognitive empathy through learned notions of moral duty.

Meanwhile, Northwest European societies have had their capacity for empathy pushed to the limit, as seen in the commonly heard term "aid fatigue." And there is no easy way to turn it off. The only real way is to convince oneself that the object of empathy is morally worthless.

Was it all an evolutionary mistake? Time will tell.

 

References

Chakrabarti, B. and S. Baron-Cohen. (2013). Understanding the genetics of empathy and the autistic spectrum, in S. Baron-Cohen, H. Tager-Flusberg, M. Lombardo. (eds). Understanding Other Minds: Perspectives from Developmental Social Neuroscience, Oxford: Oxford University Press.

http://books.google.ca/books?hl=fr&lr=&id=eTdLAAAAQBAJ&oi=fnd&pg=PA326&ots=fHpygaxaMQ&sig=_sJsVgdoe0hc-fFbzaW3GMEslZU#v=onepage&q&f=false  

Hajnal, J. (1965). European marriage pattern in historical perspective. In D.V. Glass and D.E.C. Eversley (eds). Population in History, Arnold, London.

Hallam, H.E. (1985). Age at first marriage and age at death in the Lincolnshire Fenland, 1252-1478, Population Studies, 39, 55-69.

Hawks, J., E.T. Wang, G.M. Cochran, H.C. Harpending,& R.K. Moyzis. (2007). Recent acceleration of human adaptive evolution. Proceedings of the National Academy of Sciences (USA), 104, 20753-20758.

http://harpending.humanevo.utah.edu/Documents/accel_pnas_submit.pdf

Lepowsky, M. (2011). The boundaries of personhood, the problem of empathy, and "the native's point of view" in the outer islands, in D.W. Hollan, C. J. Throop (eds).The Anthropology of Empathy: Experiencing the Lives of Others in Pacific Societies, (pp. 43-68), New York: Berghahn.

Price, T.D. (1991). The Mesolithic of Northern Europe, Annual Review of Anthropology, 20, 211-233.

http://www.cas.umt.edu/departments/anthropology/courses/anth254/documents/annurev.an.TDouglasPrice1991MseolithicNEurope.pdf  

 

Seccombe, W. (1992). A Millennium of Family Change. Feudalism to Capitalism in Northwestern Europe, London: Verso.

Siu, A.M.H. and D.T. L. Shek. (2005). Validation of the Interpersonal Reactivity Index in a Chinese Context, Research on Social Work Practice, 15, 118-126.

http://rsw.sagepub.com/content/15/2/118.short

Dear Fred

In a recent post, Fred Reed asks:

Why should I not indulge my hobby of torturing to death the severely genetically retarded? This would seem beneficial. We certainly don't want them to reproduce, they use resources better invested in healthy children, and it makes no evolutionary difference whether they die quietly or screaming.

The short answer is that any killing, for whatever reason, increases the likelihood of killing for other reasons. One exception is self-defence, but that's not done for pleasure. Another exception is capital punishment, but that, too, is not done for pleasure. More to the point, no single citizen can carry out an execution. It requires a lengthy judicial process. The same reasoning applies to the final exception of war. No single citizen can declare war.

It's not for nothing that killing is so taboo, especially recreational killing. Several things have contributed to the success of Western societies, but a leading one is the relatively peaceful nature of social relations. When people can go about their business without fearing for their lives, much becomes possible that otherwise would not be. This taboo is so crucial that we even extend it to nonhumans. Cats and dogs have no inherent right to life, yet it is a serious offence to torture them to death.

 

That's society. What about biology?

At this point, Fred may speak up: "But those are social reasons against killing of any sort. What are the biological reasons?"

The immediate biological reason is empathy. If I try to hurt someone, I feel the pain I inflict. Truth be told, the only life forms I enjoy killing are flies and mosquitoes. If a moth flies into our home, I'll go to some length to capture it and set it free outside, and I know others who do similar things. Just think of all the car drivers who come to a screeching halt to avoid running over some poor animal.

It's empathy that makes me and others act that way. And I cannot easily turn it off. It shuts down only when feelings of contempt enter my mind, as with those contemptible flies and mosquitoes.

Empathy is hardwired. It's 68% heritable in the case of affective empathy, i.e., the capacity to respond with the appropriate emotion to another person's mental state (Chakrabarti and Baron-Cohen, 2013). To date, studies have focused on disorders caused by too much empathy or too little. Psychopaths may have intact cognitive empathy, but impaired affective empathy. They keenly understand how others feel without actually experiencing those feelings. The reverse impairment may affect autists. As for depressives, they may suffer from being too sensitive to the distress of others and to guilt over not helping them enough.

 

These disorders exist at the tail ends of a normal distribution. By focusing on these extremes, we forget the variability among healthy individuals. We all vary in our capacity for empathy, just as we do for almost any mental capacity.

 

How can evolution explain empathy?

Why do we feel empathy? How could natural selection favor such selflessness? This is of course the point that Fred is trying to make. Empathy keeps us from doing things that supposedly make evolutionary sense. Therefore, it could not have evolved. It must have been given to us by a Great Designer.

But why did this Great Designer give more of it to some people than to others? We're talking about a heritable trait. It's not as if everyone starts off the same way, with some later falling behind through their own wrongdoing.

And how has the Great Designer preserved this selfless behavior? Unless something is done, empathic people will eventually be overwhelmed by a tidal wave of cheaters, free riders, and people shouting "Gimme! Gimme! Gimme!" This is as much a mystery for creationists as it is for evolutionists. It's one thing to explain how altruism came to be. It's another to explain how it manages to survive in this cynical world.

These questions passed through my mind when I was going through my late mother's effects. I discovered she had for years been donating money for various projects in the Third World, at a time when she was a widow with no pension. Meanwhile, as a teenager, I had to take on all kinds of odd jobs to help us make ends meet. Looking over those donor receipts I shook my head and felt some resentment. How do good Christians like her manage to survive?

Yet she did, like others before her. For one thing, she was suspicious of strangers, and this suspicion extended to some ethnic groups more than to others. She was prejudiced and "postjudiced." If someone acted dishonestly with her once too often, she would have no more to do with him or her. Such people were "contemptible."

Today, that sort of behavior might seem un-Christian. But her Christianity was of an older, judgmental sort, being inspired more by the punitive Old Testament than by the forgiving New Testament. She would judge people, and her judgment could be harsh, very harsh.

 

Over space and time

Just as the capacity for empathy varies from one individual to another, it also varies statistically from one human population to another, being strongest in the "guilt cultures" of Northwest Europe. Guilt is the twin sister of empathy. Both flow from a simulation of how another person thinks or feels (an imaginary witness to a wrongdoing, a person in distress) and both ensure correct behavior by inducing the appropriate feelings (anguish, pity).

Why are guilt and empathy so strong in Northwest Europeans? Other societies ensure good behavior by relying on close kin to step in and enforce social rules. This policing mechanism has been less effective west of the Hajnal line (which runs roughly from Trieste to St. Petersburg) because kinship ties have been correspondingly weaker. There has thus been stronger selection for internal means of behavior control, like guilt and empathy.

This zone of relatively weak kinship is associated with unusual demographic tendencies, called the Western European Marriage Pattern:

- relatively late marriage for men and women

- many people who never marry

- neolocality (children leave the family household to form new households)

- high circulation of non-kin among different households (Hajnal, 1964; ICA, 2013)

The Western European Marriage Pattern was thought to have arisen after the Black Death of the 14th century. There is now good evidence for its existence before the Black Death and fragmentary evidence going back to 9th century France and earlier (Hallam, 1985; Seccombe, 1992, p. 94). Historian Alan Macfarlane likewise sees an English tendency toward weaker kinship ties before the 13th century and even during Anglo-Saxon times (Macfarlane, 2012; Macfarlane, 1992, pp. 173-174). I have argued that this tendency probably goes still farther back (Frost, 2013a; Frost, 2013b).

 

Whatever the ultimate cause, Northwest Europeans seem to have been pre-adapted for later shifts away from kinship and toward alternate means of organizing social relations (i.e., ideology, codified law, commerce). This tendency has taken various forms: the intense guilt-driven Christianity of the Anglo-Saxon penitential tradition and, later, Protestantism; the medieval alliance between Church and State to pacify social relations; and the post-medieval rise of the market economy. This cultural evolution has been described by the historical economist Gregory Clark for the English population between the 12th and 19th centuries. As England became a settled society, success went to those who could resolve disputes amiably and profit from thinking ahead—in short, those who had middle-class values of thrift, foresight, self-control, nonviolence, and sobriety. This English middle class, initially tiny, grew in numbers until its lineages accounted for most of its country’s gene pool (Clark, 2007; Clark, 2009a; Clark, 2009b).

 

But what does that have to do with evolution???

 

At this point, Fred may again speak up, with more than a touch of exasperation: "You're ducking my question! You're talking about culture, society, and religion! What does that have to do with evolution???"

Everything, Fred. Everything. Unlike other animals, humans have to adapt not only to their physical environment but also to their cultural environment. In short, we've become participants in our own evolution. We have domesticated ourselves.

Let me return to your initial question. What's to stop you from torturing to death the severely retarded? First, your sense of empathy should. If it doesn't, you're the one with a severe mental defect. I wouldn't want you as a fellow citizen, let alone as a neighbor. The law of the jungle may give you the right to torture defenceless people to death, but it also gives me the right to organize a lynch mob and hang you from the nearest tree.

 

References

Chakrabarti, B. and S. Baron-Cohen. (2013). Understanding the genetics of empathy and the autistic spectrum, in S. Baron-Cohen, H. Tager-Flusberg, M. Lombardo. (eds). Understanding Other Minds: Perspectives from Developmental Social Neuroscience, Oxford: Oxford University Press.

Clark, G. (2007). A Farewell to Alms. A Brief Economic History of the World, Princeton: Princeton University Press.

Clark, G. (2009a). The indicted and the wealthy: Surnames, reproductive success, genetic selection and social class in pre-industrial England.

http://www.econ.ucdavis.edu/faculty/gclark/Farewell%20to%20Alms/Clark%20-Surnames.pdf 

 

Clark, G. (2009b). The domestication of man: The social implications of Darwin. ArtefaCTos, 2, 64-80.

http://campus.usal.es/~revistas_trabajo/index.php/artefactos/article/viewFile/5427/5465

Frost, P. (2013a). The origins of Northwest European guilt culture, Evo and Proud, December 7

http://evoandproud.blogspot.ca/2013/12/the-origins-of-northwest-european-guilt.html

 

Frost, P. (2013b). Origins of Northwest European guilt culture, Part II, Evo and Proud, December 14

http://evoandproud.blogspot.ca/2013/12/origins-of-northwest-european-guilt.html

Hajnal, John (1965). European marriage pattern in historical perspective. In D.V. Glass and D.E.C. Eversley (eds). Population in History. Arnold, London.

Hallam, H.E. (1985). Age at first marriage and age at death in the Lincolnshire Fenland, 1252-1478, Population Studies, 39, 55-69.

 

ICA (2013). Research Themes - Marriage Patterns, Institutions for Collective Action

http://www.collective-action.info/_THE_MarriagePatterns_EMP 

 

Macfarlane, A. (1992). On individualism, Proceedings of the British Academy, 82, 171-199.

http://www.alanmacfarlane.com/TEXTS/On_Individualism.pdf 

 

Macfarlane, A. (2012). The invention of the modern world. Chapter 8: Family, friendship and population, The Fortnightly Review, Spring-Summer serial

http://fortnightlyreview.co.uk/2012/07/invention-8/

Seccombe, W. (1992). A Millennium of Family Change. Feudalism to Capitalism in Northwestern Europe, London: Verso.

 

A new start

 

When geneticist Davide Piffer examined IQ-enhancing alleles at seven different genes, he found that their average prevalence differed among human populations, being highest in East Asians and lowest in Mbuti Pygmies (photo used with author's approval)

 

My weekly posts are now appearing on The Unz Review (http://www.unz.com/). By accepting Ron's invitation, I hope to reach a bigger audience and bring myself closer to other writers in the area of human biodiversity. When people work together, or simply alongside each other, minor differences can be ironed out and major differences narrowed or at least accepted good-naturedly. One thing I've learned is that academic debate can leave a legacy of hurt feelings. The impersonal can become personal, partly because people feel attached to their views and partly because views themselves can have personal impacts.

Working together also creates synergy. It becomes easier to identify research priorities, contact interested researchers, and end up with publishable findings. At present, most HBD research involves trawling through the literature and offering new interpretations. That's fine, but we need lab work as well. This point came up in a 2006 interview with geneticist Bruce Lahn:
 

A lot of researchers studying human population genetics and evolution are strictly data miners (i.e., they generate/publish no original data). There are limitations to such an approach, as it depends on the available data and prevents certain analyses from being performed. Do you expect to see more research groups turning into pure data mining labs in the future? Or will there still be a place for independent labs generating their own data (for example, resequencing a gene in multiple individuals to study the polymorphism)?

Given the explosion of genomic data in the last decade or so, which shows no sign of slowing down any time soon, there is likely to be a proliferation of pure data miners just because there is a niche for them. But I suspect that many interesting findings will still require the combination of data mining and wet experiments to provide key pieces of data not already available in public databases. In this regard, labs that can do both data mining and wet experiments can have an advantage over labs that can only do data mining. (Gene Expression, 2006)

Lab work will probably have to be offshored, not because it's cheaper to do elsewhere but because the "free world" is no longer the best place for unimpeded scientific inquiry.  A Hong Kong team is conducting a large-scale investigation into the genetics of intelligence, and nothing comparable is being done in either North America or Western Europe. Cost isn't the reason.

A few suggestions for research:

 

Human variation in IQ-enhancing alleles

We know that human intellectual capacity has risen through small incremental changes at very many genes, probably hundreds if not thousands. Have these changes been the same in all populations?

Davide Piffer (2013) has tried to answer this question by using a small subset of these genes. He began with seven SNPs whose different alleles are associated with differences in performance on PISA or IQ tests. Then, for fifty human populations, he looked up the prevalence of each allele that seems to increase performance. Finally, for each population, he calculated the average prevalence of these alleles at all seven genes.

The average prevalence was 39% among East Asians, 36% among Europeans, 32% among Amerindians, 24% among Melanesians and Papuan-New Guineans, and 16% among sub-Saharan Africans. The lowest scores were among San Bushmen (6%) and Mbuti Pygmies (5%). A related finding is that all but one of the alleles are specific to humans and not shared with ancestral primates.

Yes, he was using a small subset of genes that influence intellectual capacity. But you don't need a big number to get the big picture. If you dip your hand into a barrel of differently colored jelly beans, the colors you see in your hand will match well enough what's in the barrel. In any case, if the same trend holds up with a subset of 50 or so genes, it will be hard to say it's all due to chance.

 

Interaction between age and intellectual capacity

These population differences seem to widen after puberty, as Franz Boas noted a century ago (Boas, 1974, p. 234). It may be that general intelligence was largely confined to early childhood in ancestral humans, as a means to integrate information during the time of life when children become familiar with their surroundings. With increasing age, and familiarity, this learning capacity would shut down. When modern humans began to enter environments that had higher cognitive demands, natural selection may have favored retention of general intelligence in adulthood, just as it favored retention of the capacity to digest lactose wherever adults raised dairy cattle and drank milk.

After doing a principal component analysis on covariance between the above IQ-enhancing alleles and performance on IQ and Pisa tests, Piffer (2013) was able to identify three alleles that show the highest loading on the first component. Ward et al. (2014) have found that possession of these three alleles correlates with educational performance of 13 to 14 year old children. We now have a tool to measure the interaction between genes and age in the development of intellectual capacity, particularly during the critical period extending from pre-puberty to early adulthood.

 

Convergent evolution

Some human populations seem to have arrived at similar outcomes through different evolutionary trajectories. East Asians, for instance, resemble Western Europeans in their level of societal development, but this similar outcome has been achieved through a different mental and behavioral package, specifically lower levels of guilt and empathy with correspondingly higher levels of shame and prosocial behavior. In short, East Asians tend to enforce social rules more by external mediation (e.g., shaming, peer pressure, family discipline) than by internal control (e.g., guilt, empathy).

This difference probably reflects a mix of learned and innate predispositions, since natural selection favors whatever works, regardless of how hardwired it may or may not be. To the extent that these predispositions are hardwired, East Asians may be less able to cope with the sort of aloneness, anonymity, and individualism we take for granted.

It would be easy enough to study the neurological effects of social isolation on East Asians, and there is already suggestive evidence that such effects include unusual outbursts of psychotic behavior. It would be harder, however, to determine whether this malfunctioning has a heritable component.

 

Microcephalin - Why does its Eurasian allele increase brain volume?

Almost a decade ago, Bruce Lahn was among those who discovered that a gene involved in brain growth, Microcephalin, continued to evolve after modern humans had spread out of Africa. Its most recent allele arose some 37,000 years ago in Eurasia and is still largely confined to native Eurasians and Amerindians (Evans et al., 2005). Interest in this finding evaporated when no significant correlation was found between the Eurasian allele and higher scores on IQ tests (Mekel-Bobrov et al, 2007; Rushton et al., 2007). Nonetheless, a later study showed that this allele correlates with increased brain volume (Montgomery and Mundy, 2010).

The time of origin corresponds to the entry of modern humans into seasonal temperate environments. It also corresponds to the beginnings of Upper Paleolithic art—realistic 3D representations of game animals on stone, clay, bone, and ivory. The common denominator seems to be an increased capacity to store spatiotemporal information, i.e., the ability to imagine objects, particularly game animals, and how they move over space and time. If IQ tests fail to measure this capacity, it may be worthwhile to test carriers of this allele for artistic or map-reading skills.

 

ASPM - Does the Middle Eastern/West Eurasian allele assist processing of alphabetical script?

ASPM is another gene that regulates brain growth, and like Microcephalin it continued to evolve after modern humans had spread out of Africa, its latest allele arising about 6000 years ago somewhere in the Middle East. The new allele then proliferated within and outside this region, reaching higher incidences in the Middle East (37-52%) and in Europe (38-50%) than in East Asia (0-25%). Despite its apparent selective advantage, this allele does not seem to improve cognitive performance on standard IQ tests. On the other hand, there is evidence that it is associated with increased brain size (Montgomery and Mundy, 2010).

At present, we can only say that it probably assists performance on a task that exhibited the same geographic expansion from a Middle Eastern origin roughly 6000 years ago. The closest match seems to be the invention of alphabetical writing, specifically the task of transcribing speech and copying texts into alphabetical script. Though more easily learned than ideographs, alphabetical characters place higher demands on mental processing, especially under premodern conditions (continuous text with little or no punctuation, real-time stenography, absence of automated assistance for publishing or copying, etc.). This task was largely delegated to scribes of various sorts who enjoyed privileged status and probably superior reproductive success. Such individuals may have served as vectors for spreading the new ASPM allele (Frost, 2008; Frost, 2011).

 

Tay Sachs and IQ

Ashkenazi Jews have high incidences of certain neurological conditions, particularly Tay Sachs, Gaucher's disease, and Niemann-Pick disease. In the homozygous state these conditions are deleterious, but in the heterozygous state they may improve intellectual capacity by increasing neural axis length and branching. Cochran et al. (2006) argue that this improvement could amount to about 5 IQ points.

There was in fact a study in the 1980s to determine whether Tay-Sachs heterozygotes suffer from mental deficits (Kohn et al., 1988). The authors found no deficits but did not elaborate on whether performance was above-normal on the neuropsychological tests. They did mention that about two thirds of the Tay-Sachs heterozygotes had education beyond high school.

The raw data seem to be long gone, but it would not be difficult to repeat the study with a view to studying above-normal mental performance in heterozygotes and non-carriers.

 

References

Boas, F. (1974). A Franz Boas Reader. The Shaping of American Anthropology, 1883-1911, G.W. Stocking Jr. (ed.), Chicago: The University of Chicago Press.

 

Cochran, G., J. Hardy, and H. Harpending. (2006). Natural history of Ashkenazi intelligence, Journal of Biosocial Science, 38, 659-693.

http://harpending.humanevo.utah.edu/trial.link/Ashkenazi.pdf

 

Evans, P. D., Gilbert, S. L., Mekel-Bobrov, N., Vallender, E. J., Anderson, J. R., Vaez-Azizi, L. M., et al. (2005). Microcephalin, a gene regulating brain size, continues to evolve adaptively in humans, Science, 309, 1717-1720.

http://www.fed.cuhk.edu.hk/~lchang/material/Evolutionary/Brain%20gene%20and%20race.pdf

 

Frost, P. (2008). The spread of alphabetical writing may have favored the latest variant of the ASPM gene, Medical Hypotheses, 70, 17-20.

http://www.sciencedirect.com/science/article/pii/S0306987707003234

Frost, P. (2011). Human nature or human natures? Futures, 43, 740-748. http://dx.doi.org/10.1016/j.futures.2011.05.017

 

Gene Expression. (2006). 10 Questions for Bruce Lahn.

http://www.gnxp.com/blog/2006/10/10-questions-for-bruce-lahn_10.php

Kohn, H., P. Manowitz, M. Miller, and A. Kling. (1988). Neuropsychological deficits in obligatory heterozygotes for metachromatic leukodystrophy, Human Genetics, 79, 8-12.

 

Mekel-Bobrov, N., Posthuma, D., Gilbert, S. L., Lind, P., Gosso, M. F., Luciano, M., et al. (2007). The ongoing adaptive evolution of ASPM and Microcephalin is not explained by increased intelligence, Human Molecular Genetics, 16, 600-608.

http://psych.colorado.edu/~carey/pdfFiles/ASPMMicrocephalin_Lahn.pdf

 

Montgomery, S. H., and N.I. Mundy. (2010). Brain evolution: Microcephaly genes weigh in, Current Biology, 20, R244-R246.

http://www.sciencedirect.com/science/article/pii/S0960982210000862

 

Piffer, D. (2013). Factor analysis of population allele frequencies as a simple, novel method of detecting signals of recent polygenic selection: The example of educational attainment and IQ, Mankind Quarterly, 54, 168-200.

http://emilkirkegaard.dk/en/wp-content/uploads/Factor-Analysis-of-Population-Allele-Frequencies-as-a-Simple-Novel-Method-of-Detecting-Signals-of-Recent-Polygenic-Selection-The-Example-of-Educational-Attainment-and-IQ.pdf 

 

Rushton, J. P., Vernon, P. A., and Bons, T. A. (2007). No evidence that polymorphisms of brain regulator genes Microcephalin and ASPM are associated with general mental ability, head circumference or altruism, Biology Letters, 3, 157-160.

http://semantico-scolaris.com/media/data/Luxid/Biol_Lett_2007_Apr_22_3(2)_157-160/rsbl20060586.pdf 

 

Ward, M.E., G. McMahon, B. St Pourcain, D.M. Evans, C.A. Rietveld, et al. (2014). Genetic variation associated with differential educational attainment in adults has anticipated associations with school performance in children. PLoS ONE 9(7): e100248. doi:10.1371/journal.pone.0100248

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0100248#pone-0100248-g002

How universal is empathy?

 

Bronislaw Malinowski with natives on the Trobriand Islands (1918 - source). Pro-social behavior seems to be a human universal, but is the same true for full empathy?

 

What is empathy? It has at least three components:

- pro-social behavior, i.e., actions of compassion to help others

- cognitive empathy, i.e., capacity to understand another person's mental state

- affective or emotional empathy, i.e., capacity to respond with the appropriate emotion to another person's mental state (Chakrabarti and Baron-Cohen, 2013)

In their review of the literature, Chakrabarti and Baron-Cohen (2013) conclude that all three components are moderately to highly heritable, although the affective component seems to show the highest heritability (68%). This is in line with Davis et al. (1994), who found significant heritability for the affective facets of empathy (empathic concern and personal distress) but not for non-affective perspective taking.

All three components can vary from one individual to another, although studies to date have focused on pathological variation:

For example, it is suggested that people with psychopathic personality disorder may have intact cognitive empathy (hence being able to deceive others), but impaired affective empathy (hence being able to hurt others), whilst people with autism may show the opposite profile (hence finding the social world confusing because of their deficit in cognitive empathy, but not being over-represented among criminal offenders, having no wish to hurt others, suggesting their affective empathy may be intact) (Chakrabarti and Baron-Cohen, 2013)

People with depression may suffer from too much empathy, i.e., being too sensitive to the needs or distress of others (O'Connor et al., 2007). In short, these disorders seem to be the tail ends of a normal distribution. By focusing on these extremes, we forget that most of the genetic variability in empathy occurs among healthy individuals (Gillberg, 2007).

 

Using research findings on autism and Asperger syndrome, Chakrabarti and Baron-Cohen (2013) have identified nine candidate genes that seem to promote empathy. They fall into three functional categories: sex-steroid synthesis and metabolism; neural development and connectivity; and social-emotional responsivity. The first category includes the degree to which a fetus is androgenized or estrogenized before birth, as shown by digit ratio (Frost, 2014).

 

Variation among human populations

If the genes associated with empathy vary among healthy individuals, do they also vary among human populations? This would be expected because populations have differed in their needs for different components of empathy, particularly since hunting and gathering gave way to farming some 10,000 years ago—when genetic change speeded up over a hundred-fold. At that time, humans were no longer adapting to new physical environments. They were adapting to new cultural environments that differed in social structure, in division of labor, in means of subsistence, in norms of conduct, in future time orientation, in degree of sedentary living, and so on. Our ancestors were now reshaping their environments, and these human-made environments were now reshaping them—in other words, gene-culture co-evolution (Hawks et al., 2007).

Humans have been transformed especially by the shift from small bands of hunter-gatherers to larger and more complex groups of farmers and townsfolk. With social relations expanding beyond the circle of close kin, kinship obligations were no longer enough to ensure mutual assistance and stop free riding. There was thus selection for pro-social behavior, i.e., a spontaneous willingness to help not only kin but also non-kin.

Pro-social behavior is attested across a wide range of cultures. It is the subject of a recent book about the nature and limits of empathy in Oceanic cultures. The Banabans of Fiji for instance express the idea of pro-sociality through the term nanoanga, which they normally translate into English by "compassion" or "pity."

[...] compassion is the basis for their capacity to bond socially with others, even compassion to the point of readiness to take strangers into their community. Their empathy therefore relates causally to how they act socially toward others. Here compassion or pity embraces both understanding and fellow feeling: the islanders understand that the stranded mariner is at the end of his strength, which is why they succor him and treat him as one of their own. They understand him because he, like them, is a human being, a person. [...] Thus, for example, when someone passing by a house does not belong to the immediate family of those inside, it is customary to welcome the passer-by by calling out the words mai rin! (Come in!), which carry the implication that food and drink will not be found wanting inside. (Hermann, 2011, p. 31)

This desire to help non-kin is not unconditional. The author notes that prior experiences with an individual in distress can determine whether compassion will be given or withheld. Moreover, Barnabans can "proceed strategically when deciding whether to extend trust to others or to keep thoughts and feelings to themselves" (Hermann, 2011, p. 31). This is not the affective empathy of entering another person's mind to feel his or her pain.

 

When the Barnabans compare themselves with others, and when by their behavior toward the stranger they show that they understand him and feel with him, they do not, however, equate themselves fully and entirely with him. (Hermann, 2011, p. 32)

 

Another contributor to the same book writes similarly about the inhabitants of Vanatinai, in the Trobriand Islands.

 

On the island of Vanatinai, when someone, including an ethnographer, privately asks a trusted confidant, "Why did she/he act like that?" "What was she/he thinking?" the common answer, often uttered in tones of puzzlement and despair, or anxiety and fear, expresses one of the islanders' core epistemological principles: "We cannot know their renuanga." Renuanga is a word that refers to a person's inner experiences, both and inseparably thought and emotion.

 

[...] And their psychic states, their inner thought and feelings, are inherently unknowable. It may never be clear why they were angry or sympathetic, and what caused them to act and influence an event in someone's life [...] (Lepowsky, 2011, p. 44)

 

In short, Oceanic cultures display hospitality but not full empathy, which would be considered undesirable anyway:

The philosophical principle of personal opacity, the interiority of others' thoughts/feelings (renuanga), is closely bound to the islanders' fierce insistence on personal autonomy, both as cultural ideology and as daily social practice (Lepowsky, 2011, p. 47)

 

From pro-sociality to full empathy

Whereas pro-sociality is attested across a wide range of cultures, full cognitive/affective empathy is more localized. The difference is like the one we see between shame and guilt. Most cultures primarily use shame to enforce correct behavior, i.e., if other people see you breaking a rule, you feel ashamed and this feeling is reinforced by social disapproval. In contrast, only a minority of cultures—largely those of Northwest Europe—rely primarily on guilt, which operates even when only you see yourself breaking a rule or merely think about breaking a rule (Benedict, 1946; Creighton, 1990).

Northwest Europeans have thus undergone two parallel changes in behavioral control: 1) a shift from pro-sociality to full cognitive/affective empathy; and 2) a shift from shame to guilt. Indeed, full empathy and guilt may be two sides of the same coin. Both are the consequences of a mental model that is used to simulate how another person thinks or feels (an imaginary witness to a wrongful act, a person in distress) and to ensure correct behavior by inducing the appropriate feelings (anguish, pity).

Finally, full empathy and guilt are most adaptive where kinship ties are relatively weak and where rules of correct behavior require a leveling of the playing field between kin and non-kin. This has long been the case in Northwest Europe. There seems to be a longstanding pattern of weak kinship ties west of a line running from Trieste to St. Petersburg, as shown by several culture traits that are rare or absent elsewhere:

- relatively late marriage for men and women

- many people who never marry

- neolocality (children leave the family household to form new households)

- high circulation of non-kin among different households (typically young people sent out as servants) (Hajnal, 1965)

Commonly called the Western European Marriage Pattern, this geographic zone of relatively weak kinship was thought to have arisen after the Black Death of the 14th century. There is now good evidence for its existence before the Black Death and fragmentary evidence going back to 9th century France and even earlier (Hallam, 1985; Seccombe, 1992, p. 94). Historian Alan Macfarlane likewise sees an English tendency toward weaker kinship ties before the 13th century and even during Anglo-Saxon times (Macfarlane, 2012; Macfarlane, 1992, pp. 173-174).

This weak kinship zone may have arisen in prehistory along the coasts of the North Sea and the Baltic, which were once home to a unique Mesolithic culture (Price, 1991). An abundance of marine resources enabled hunter-fisher-gatherers to achieve high population densities by congregating each year in large coastal agglomerations for fishing, sealing, and shellfish collecting. Population densities were comparable in fact to those of farming societies, but unlike the latter there was much "churning" because these agglomerations formed and reformed on a yearly basis. Kinship obligations would have been insufficient to resolve disputes peaceably, to manage shared resources, and to ensure respect for social rules. Initially, peer pressure was probably used to get people to see things from the other person's perspective. Over time, however, the pressure of natural selection would have favored individuals who more readily felt this equivalence of perspectives, the result being a progressive hardwiring of compassion and shame and their gradual transformation into empathy and guilt (Frost, 2013a; Frost, 2013b).

Empathy and guilt are brutally effective ways to enforce social rules. If one disobeys these internal overseers, the result is self-punishment that passes through three stages: anguish, depression and, ultimately, suicidal ideation.

People suffering from depression are looking at both others and themselves with suspicion, often believing whatever they have was obtained by cheating, and that it is more than they deserve. Depressives, burdened by moralistic standards, are harsh evaluators of both themselves and others. The self-punishment meted out by depressives is a common if disturbing symptom; while thinking 'I deserve this', they may engage in altruistic punishment turned upon the self. Just as altruistic punishers experience a neuronally based reward from punishing defectors, despite material costs, depressed patients report a sense of relief upon inflicting self-punishment. Patients who are 'cutters', describe relief from tension after cutting and depressives with suicidal ideation may describe the relief they felt when on the verge of attempting a suicidal action. (O'Connor et al., 2007, p. 67)

This pathology is progressively less common in populations farther south and east, not so much because each stage is less common but rather because depression is much less likely to result from empathic guilt and much less likely to lead to suicide (Stompe et al., 2001). This 3-stage sequence does not seem to be a human universal, at least not to the same extent as in Northwest Europeans, a reality that Frantz Fanon noted when describing clinical depression in Algerians:

 

French psychiatrists in Algeria found themselves faced with a difficult problem. When treating a melancholic patient, they were accustomed to being afraid of suicide. The melancholic Algerian kills, however. This disease of the moral conscience that is always accompanied by self-accusation and self-destructive tendencies assumes hetero-destructive forms in the Algerian. The melancholic Algerian does not commit suicide. He kills. (Fanon, 1970, pp. 219-220)

 

References

Benedict, R. (1946 [2005]). The Chrysanthemum and the Sword. Patterns of Japanese Culture, First Mariner Books.

 

Chakrabarti, B. and S. Baron-Cohen. (2013). Understanding the genetics of empathy and the autistic spectrum, in S. Baron-Cohen, H. Tager-Flusberg, M. Lombardo. (eds). Understanding Other Minds: Perspectives from Developmental Social Neuroscience, Oxford: Oxford University Press.

http://books.google.ca/books?hl=fr&lr=&id=eTdLAAAAQBAJ&oi=fnd&pg=PA326&ots=fHpygaxaMQ&sig=_sJsVgdoe0hc-fFbzaW3GMEslZU#v=onepage&q&f=false

 

Creighton, M.R. (1990). Revisiting shame and guilt cultures: A forty-year pilgrimage, Ethos, 18, 279-307.

http://sfprg.org/control_mastery/docs/revisitshameguilt.pdf

Davis, M.H., C. Luce, and S.J. Kraus. (1994). The heritability of characteristics associated with dispositional empathy, Journal of Personality, 62, 369-391.

Fanon, F. (1970). Les damnés de la terre, Paris: Maspero.

 

Frost, P. (2013a). The origins of Northwest European guilt culture, Evo and Proud, December 7

http://evoandproud.blogspot.ca/2013/12/the-origins-of-northwest-european-guilt.html

 

Frost, P. (2013b). Origins of Northwest European guilt culture, Part II, Evo and Proud, December 14

http://evoandproud.blogspot.ca/2013/12/origins-of-northwest-european-guilt.html

 

Frost, P. (2014). A pathway to pro-social behavior, Evo and Proud, May 10.

http://evoandproud.blogspot.ca/2014/05/a-pathway-to-pro-social-behavior.html

Gillberg, C. (2007). Non-autism childhood personality disorders, in: T.F.D. Farrow and P.W.R. Woodruff (eds). Empathy in Mental Illness, (pp. 111-125). Cambridge: Cambridge University Press.

Hajnal, J. (1965). European marriage pattern in historical perspective. In D.V. Glass and D.E.C. Eversley (eds). Population in History, Arnold, London.

Hallam, H.E. (1985). Age at first marriage and age at death in the Lincolnshire Fenland, 1252-1478, Population Studies, 39, 55-69.

 

Hawks, J., E.T. Wang, G.M. Cochran, H.C. Harpending, & R.K. Moyzis. (2007). Recent acceleration of human adaptive evolution. Proceedings of the National Academy of Sciences (USA), 104, 20753-20758.

http://harpending.humanevo.utah.edu/Documents/accel_pnas_submit.pdf

Hermann, E. (2011). Empathy, ethnicity, and the self among the Barnabans in Fiji, in D.W. Hollan, C. J. Throop (eds).The Anthropology of Empathy: Experiencing the Lives of Others in Pacific Societies, (pp. 25-42), New York: Berghahn.

Lepowsky, M. (2011). The boundaries of personhood, the problem of empathy, and "the native's point of view" in the outer islands, in D.W. Hollan, C. J. Throop (eds).The Anthropology of Empathy: Experiencing the Lives of Others in Pacific Societies, (pp. 43-68), New York: Berghahn.

 

Macfarlane, A. (1992). On individualism, Proceedings of the British Academy, 82, 171-199.

http://www.alanmacfarlane.com/TEXTS/On_Individualism.pdf

 

Macfarlane, A. (2012). The invention of the modern world. Chapter 8: Family, friendship and population, The Fortnightly Review, Spring-Summer serial

http://fortnightlyreview.co.uk/2012/07/invention-8/

O'Connor, L.E., J.W. Berry, T. Lewis, K. Mulherin, and P.S. Crisostomo. (2007). Empathy and depression: the moral system in overdrive, in: T.F.D. Farrow and P.W.R. Woodruff (eds). Empathy in Mental Illness, (pp. 49-75). Cambridge: Cambridge University Press.

 

http://www.eparg.org/publications/empathy-chapter-web.pdf

Price, T.D. (1991). The Mesolithic of Northern Europe, Annual Review of Anthropology, 20, 211-233.

http://www.cas.umt.edu/departments/anthropology/courses/anth254/documents/annurev.an.TDouglasPrice1991MseolithicNEurope.pdf

Seccombe, W. (1992). A Millennium of Family Change. Feudalism to Capitalism in Northwestern Europe, London: Verso.

Stompe, T., G. Ortwein-Swoboda, H.R. Chaudhry, A. Friedmann, T. Wenzel, and H. Schanda. (2001). Guilt and depression: a cross-cultural comparative study, Psychopathology, 34, 289-298.