Evolution of empathy, part II

Medical students, Monterrey (credit: Daniel Adelrio, Wikicommons). Mexicans feel more empathy if they have a university degree. Does university make people more empathic?

We differ from individual to individual in our capacity not only to understand how others feel but also to experience their pain or joy. This “affective empathy” also differs between the sexes, being stronger in women than in men. Does it also differ between human populations? It should, for several reasons: 

- Affective empathy is highly heritable. A recent study put its heritability at 52-57% (Melchers et al. 2016).

- It differs in adaptiveness from one cultural environment to another, being adaptive in high-trust cultures and maladaptive in low-trust ones. There has thus been a potential for gene-culture coevolution.

- Such an evolutionary scenario would require relatively few genetic changes. Affective empathy exists in all human populations, and most likely already existed in ancestral hominids. Differences within our species are thus differences in fine-tuning of an existing mechanism. 

One can imagine the following scenario:

1. Initially, affective empathy existed primarily in women and served to facilitate the mother-child relationship.

2. Later, when human societies grew beyond the size of small kin groups, this mental trait took on a new task: regular interaction with people who were not necessarily close kin.

3. Selection thus increased the capacity for affective empathy in both sexes but more so in men.

4. This gene-culture evolution went the farthest in high-trust cultures.

Affective empathy and educational level in Mexico

To measure differences in affective empathy between human populations we can administer tests like "Pictures of Facial Affect" and the "Cambridge Behavior Scale." The first test is a measure of the ability to recognize emotion in human faces. The second test is a questionnaire with responses on a 4-point scale ranging from "strongly agree" to "strongly disagree."

In a recent study from Mexico these tests confirmed that affective empathy is stronger in women than in men. There were also differences by occupational status:

[...] we sought to explore facial emotion recognition abilities and empathy in administrative officers and security guards at a center for institutionalized juvenile offenders. One hundred twenty-two Mexican subjects, including both men and women, were recruited for the study. Sixty-three subjects were administrative officers, and 59 subjects were security guards at a juvenile detention center. Tasks included "Pictures of Facial Affect" and the "Cambridge Behavior Scale." The results showed that group and gender had an independent effect on emotion recognition abilities, with no significant interaction between the two variables. Specifically, administrative officers showed higher empathy than security guards. Moreover, women in general exhibited more empathy than men. (Quintero et al. 2018)

Why were the guards less able to recognize signs of distress or happiness on human faces? The authors offer no explanation but do note that the two groups differed in educational level: most of the administrative officers were university graduates, whereas the guards had gone no farther than middle school. 

In Mexico, educational level correlates with European admixture (Martinez-Marignac et al. 2007). Is this group difference in empathy really an ethnic difference?

The amygdala and political orientation in the U.S. and the U.K.

Tests are subjective and thus suffer from biases that may produce different results in different populations. To avoid this problem, a promising method is to measure the size or activity of brain structures that are associated with affective empathy. In the latest review of the literature, Tal Saban and Kirby (2019) assign the amygdala a key role:

Neuroscientists have identified the brain regions for the "empathy circuit": 1) the amygdala, responsible for regulating emotional learning and reading emotional expressions; 2) the anterior cingulate cortex (ACC), activated during observed or experienced pain in the self or others; and 3) the anterior insula (AI), which responds to one's pain and the pain of a loved one (Carr, Iacoboni, Dubeau, Mazziotta, & Lenzi, 2003). In recent years the mirror neuron system (MNS), comprised of the inferior frontal gyrus and inferior parietal cortex, has been suggested to also be involved in empathy (Gazzola et al., 2006, Kaplan and Iacoboni, 2006, Pfeifer et al., 2008, Baird et al., 2011). The broad notion that empathy involves "putting oneself in another's shoes" by simulating what others do, think, or feel, has been linked to the properties of mirror neurons.

The amygdala has been linked to affective empathy by MRI studies on healthy individuals and on individuals with amygdala lesions (Bzdok et al. 2012; Brunnlieb et al. 2013; Gu et al. 2010; Hurlemann et al. 2010; Leigh et al. 2013).

Two studies have found group differences in amygdala size or activity. When brain MRIs were done on 82 adults from the University of California at San Diego, the right amygdala showed more activity in Republicans than in Democrats (Schreiber et al., 2013). Similarly, a study of 90 adults from University College London found that the right amygdala was larger in self-described conservatives than in self-described liberals (Kanai et al., 2011).

Is affective empathy stronger in conservatives than in liberals? Or are these labels a proxy for something else? In both the United States and England, party politics is increasingly identity politics. While it is true that non-European minorities tend to be socially conservative, they nonetheless tend to be politically liberal, often overwhelmingly so. In the American study, party affiliation was undoubtedly the dimension being measured: participants were asked whether they were Democrat or Republican. This is less evident in the English study, where participants were asked about their "political orientation."

Both universities are ethnically diverse. University of California at San Diego is 36% Asian, 20% White, 19% non-resident alien, and 17% Latino (Anon 2019). There is no ethnic breakdown of University College students, but we know that a third of them come from outside the United Kingdom (Wikipedia 2019).

Conclusion

Brain MRIs provide a means to measure affective empathy objectively. We can thus evaluate differences between human populations, just as we have evaluated differences between men and women, and from individual to individual. This kind of comparative research will likely be done by accident rather than by design, as with the above three studies.

Another approach would be to identify alleles that correlate with a high level of affective empathy. A polygenic score could then be created, thus providing an objective yardstick for measuring this mental trait in any human population. Particularly promising are two polymorphisms. Alleles at the OXTR gene correlate with inter-individual differences in empathy, especially with affective empathy in women (Huetter et al. 2016). Alleles at the GNAS gene correlate with inter-individual differences in cognitive empathy, but only in women (Huetter et al. 2018).

References

Anon. (2019). University of California - San Diego, Ethnic Diversity.

https://www.collegefactual.com/colleges/university-of-california-san-diego/student-life/diversity/#secEthnic

Bzdok, D., L. Schilbach, K. Vogeley, et al. (2012). Parsing the neural correlates of moral cognition: ALE meta-analysis on morality, theory of mind, and empathy. Brain Structure and Function 217(4):783-796. 

https://doi.org/10.1007/s00429-012-0380-y 

Brunnlieb, C., T.F. Munte, C. Tempelmann, and M. Heldmann. (2013). Vasopressin modulates neural responses related to emotional stimuli in the right amygdala. Brain Research 1499:29-42. 

Gu, X., X. Liu, K.G. Guise, et al. (2010). Functional dissociation of the frontoinsular and anterior cingulate cortices in empathy for pain. Journal of Neuroscience 30:3739-3744. 

https://doi.org/10.1016/j.brainres.2013.01.009

Huetter, F.K., H.S. Bachmann, A. Reinders, D. Siffert, P. Stelmach, D. Knop, et al. (2016). Association of a Common Oxytocin Receptor Gene Polymorphism with Self-Reported 'Empathic Concern' in a Large Population of Healthy Volunteers. PLoS ONE 11[7]:e0160059

https://doi.org/10.1371/journal.pone.0160059  

Huetter, F.K, P.A. Horn, and W. Siffert. (2018). Sex-specific association of a common GNAS polymorphism with self-reported cognitive empathy in healthy volunteers. PLoS ONE 13(10): e0206114. 

https://doi.org/10.1371/journal.pone.0206114 

Hurlemann, R., A. Patin, O.A. Onur, et al. (2010). Oxytocin enhances amygdala-dependent, socially reinforced learning and emotional empathy in humans. Journal of Neuroscience 30(14):4999-5007. 

https://doi.org/10.1523/JNEUROSCI.5538-09.2010 

Kanai, R., T. Feilden, C. Firth, and G. Rees. (2011). Political orientations are correlated with brain structure in young adults. Current Biology 21: 677 - 680.

http://www.cell.com/current-biology/abstract/S0960-9822(11)00289-2  

Leigh, R., K. Oishi, J. Hsu, et al. (2013). Acute lesions that impair affective empathy. Brain 136(8):2539-2549.

https://doi.org/10.1093/brain/awt177 

Martinez-Marignac, V.L., A. Valladares, E. Cameron, A. Chan, A. Perera, R. Globus-Goldberg, N. Wacher, J. Kumate, P. McKeigue, D. O'Donnell, M.D. Shriver, M. Cruz, and E.J. Parra. (2007). Admixture in Mexico City: implications for admixture mapping of Type 2 diabetes genetic risk factors. Human Genetics 120(6): 807-819.

https://doi.org/10.1007/s00439-006-0273-3

Melchers, M., C. Montag, M. Reuter, F.M. Spinath, and E. Hahn. (2016). How heritable is empathy? Differential effects of measurement and subcomponents. Motivation and Emotion 40(5): 720-730. 

https://doi.org/10.1007/s11031-016-9573-7  

Quintero, L.A.M., J. Muñoz-Delgado, J.C. Sánchez-Ferrer, A. Fresán, M. Brüne, and I. Arango de Montis.  (2018). Facial Emotion Recognition and Empathy in Employees at a Juvenile Detention Center. International Journal of Offender Therapy and Comparative Criminology 62(8) 2430-2446.

https://doi.org/10.1177%2F0306624X17721518 

Schreiber, D., Fonzo, G., Simmons, A.N., Dawes, C.T., Flagan, T., et al. (2013). Red Brain, Blue Brain: Evaluative Processes Differ in Democrats and Republicans. PLoS ONE 8(2): e52970.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0052970   

Tal Saban, M. and A. Kirby. (2019). Empathy, social relationship and co-occurrence in young adults with DCD. Human Movement Science 63: 62-72

https://doi.org/10.1016/j.humov.2018.11.005 

Wikipedia (2019). University College London.

http://en.wikipedia.org/wiki/University_College_London#Student_body

Feeling the other's pain

 

In the Reign of Terror, by Jessie Macgregor (1891). We don’t respond equally to signs of emotional distress in other people (Wikicommons)

We like to think that all people feel empathy to the same degree. In reality, it varies a lot from one person to the next, like most mental traits. We are half-aware of this when we distinguish between "normal people" and "psychopaths," the latter having an abnormally low capacity for empathy. The distinction is arbitrary, like the one between "tall" and "short." As with stature, empathy varies continuously among the individuals of a population, with psychopaths being the ones we find beyond an arbitrary cut-off point and who probably have many other things wrong with them. By focusing on the normal/abnormal dichotomy, we lose sight of the variation that occurs among so-called normal individuals. We probably meet people every day who have a low capacity for empathy and who nonetheless look and act normal. Because they seem normal, we assume they are as empathetic as we are. They aren’t.

Like most mental traits, empathy is heritable, its heritability being estimated at 68% (Chakrabarti and Baron-Cohen, 2013). It has two distinct components: cognitive empathy and affective empathy. Some researchers identify a third component, pro-social behavior, but its relationship to the other two seems tangential.

Cognitive empathy appears to be the evolutionarily older component of the two. It is the capacity to understand how another person is feeling and then predict how different actions will affect that person’s emotional state. But this capacity can be used for selfish purposes. Examples are legion: the con artist; many telemarketers; the rapist who knows how to charm his victims ...

Affective empathy is the younger component, having developed out of cognitive empathy. It is the capacity not just to understand another person's emotional state but also to identify with it. A person with high affective empathy will try to help someone in distress not because such help is personally advantageous or legally required, but because he or she is actually feeling the same distress.

Affective empathy may have initially evolved as a means to facilitate relations between a mother and her children. Later, and to varying degrees, it became extended to other human relationships. This evolutionary trajectory is perceptible in young children:

Children do not display empathic concern toward all people equally. Instead, they show bias toward individuals and members of groups with which they identify. For instance, young children of 2 years of age display more concern-related behaviors toward their mother than toward unfamiliar people. Moreover, children (aged 3-9 years) view social categories as marking patterns of interpersonal obligations. They view people as responsible only to their own group members, and consider within-group harm as wrong regardless of explicit rules, but they view the wrongness of between-group harm as contingent on the presence of such rules. (Decety and Cowell, 2014)

Similarly, MRI studies show that adults are much more likely to experience emotional distress when they see loved ones in pain than when they see strangers in pain. A stranger in distress will evoke a response only to the degree that the observer has a high capacity for affective empathy. The higher the capacity the more it will encompass not only loved ones but also less related individuals, including total strangers and nonhumans:

Humans can feel empathic concern for a wide range of 'others', including for nonhuman animals, such as pets (in the Western culture) or tamagotchi (in Japan). This is especially the case when signs of vulnerability and need are noticeable. In support of this, neural regions involved in perceiving the distress of other humans, such as the anterior cingulate cortex and insula, are similarly activated when witnessing the distress of domesticated animals (Decety and Cowell, 2014)

While we associate affective empathy with morality, the two are not the same, and there are situations where the two come into conflict. In most societies, kinship is the main organizing principle of social relations, and morality affirms this principle by spelling out the duties to one's parents, one's kin, and one's ethny. The importance of kinship may be seen in the Ten Commandments, which we wrongfully assume to be universal in application. We are told we must not kill, steal, lie, or commit adultery if the victims are "thy neighbor," which is explained as meaning "the children of thy people" (Leviticus 19:18). High-empathy individuals may thus subvert morality if they view all human distress as being equal in value. At best, they will neglect loved ones in order to help an indefinitely large number of needy strangers. At worst, strangers may develop strategies to exploit high-empathy individuals, i.e., to milk them for all they are worth.

Mapping empathy in the human brain

Empathy appears to arise from specific mechanisms in the brain, and not from a more general property, like general intelligence. It is produced by a sequence of mental events, beginning with "mirror neurons" that fire in tandem with the observed behavior of another person, thereby generating a mental model of this behavior. Copies of the model are sent elsewhere in the brain to decode the nature and purpose of the behavior and to predict the sensory consequences for the observed person. Affective empathy goes further by feeding these predicted consequences into the observer's emotional state (Carr et al., 2003).

Recent MRI research has confirmed that empathy is associated with increased development of certain regions within the brain. Individuals who score high on cognitive empathy have denser gray matter in the midcingulate cortex and the adjacent dorsomedial prefontal cortex, whereas individuals who score high on affective empathy have denser gray matter in the insula cortex (Eres et al.,2015). A high capacity for affective empathy is also associated with a larger amygdala, which seems to control the way we respond to facial expressions of fear and other signs of emotional distress (Marsh et al., 2014).

Can these brain regions be used to measure our capacity for affective empathy? Two studies, one American and one English, have found that "conservatives" tend to have a larger right amygdala (Kanai et al.,2011; Schreiber et al., 2013). This has been spun, perhaps predictably, as proof that the political right is fear-driven (Hibbing et al., 2014). A likelier explanation is that "conservatives" are disproportionately drawn from populations that have, on average, a higher capacity for affective empathy.

 

Do human populations vary in their capacity for affective empathy?

Is it possible, then, that this capacity varies among human populations, just as it varies among individuals? I have argued that affective empathy is more adaptive in larger, more complex societies where kinship obligations can no longer restrain behavior that seriously interferes with the ability of individuals to live together peacefully and constructively (Frost, 2015). Whereas affective empathy was originally expressed mainly between a mother and her children, it has become progressively extended in some populations to a wider range of interactions. This evolutionary change may be compared to the capacity to digest milk sugar: initially, this capacity was limited to early childhood, but in dairy cattle cultures it has become extended into adulthood.

I have also argued that this evolutionary change has gone the farthest in Europeans north and west of the Hajnal Line (Frost, 2014a). In these populations, kinship has been a weaker force in organizing social relations, at least since the early Middle Ages and perhaps since prehistoric times. There has thus been selection for mechanisms, like affective empathy, that can regulate social interaction between unrelated individuals. This selection may have intensified during two time periods:

- An initial period corresponding to the emergence of complex hunter/fisher/gatherers during the Mesolithic along the shores of the North Sea and the Baltic. Unlike other hunter-gatherers, who were typically small bands of individuals, these people were able to form large coastal communities by exploiting abundant marine resources. Such communities were beset, however, by the problem of enforcing rule compliance on unrelated people, the result being strong selection for rule-compliant individuals who share certain predispositions, namely affective empathy, proneness to guilt, and willingness to obey moral rules and to expel anyone who does not (Frost, 2013a; Frost, 2013b).

- A second period corresponding to the spread of Christianity among Northwest Europeans, particularly with the outbreeding, population growth, and increase in manorialism that followed the Dark Ages (hbd chick, 2014). The result was a "fruitful encounter" between the two: on the one hand, Christianity, with its emphasis on internalized morality, struck a responsive chord in these populations; on the other hand, the latter modified Christianity, increasing its emphasis on faith, compassion, and original sin (Frost, 2014b).

Conclusion

 

Recent research has brought much insight into the nature of empathy, which should no longer be viewed as being simply a noble precept. We now understand it as the outcome of a sequence of events in specific regions of the brain. We have also learned that individuals vary in their capacity for empathy and that most of this variability is heritable, as is the case with most mental traits. Moreover, empathy has two components—cognitive and affective—and the strength of one in relation to the other likewise varies. Although we often consider affective empathy to be desirable, it can have perverse and even pathological effects in some contexts.

References

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

 

Decety, J. and J. Cowell. (2014). The complex relation between morality and empathy, Trends in Cognitive Sciences, 18, 337-339

http://spihub.org/site/resource_files/publications/spi_wp_135_decety.pdf

 

Eres, R., J. Decety, W.R. Louis, and P. Molenberghs. (2015). Individual differences in local gray matter density are associated with differences in affective and cognitive empathy, NeuroImage, 117, 305-310.

http://www.sciencedirect.com/science/article/pii/S1053811915004206

 

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. (2014a). Compliance with Moral Norms: a Partly Heritable Trait? Evo and Proud, April 12

http://evoandproud.blogspot.ca/2014/04/compliance-with-moral-norms-partly.html

Frost, P. (2014b). A fruitful encounter, Evo and Proud, September 26

http://evoandproud.blogspot.ca/2014/09/a-fruitful-encounter.html

 

Frost, P. (2015). Two paths, The Unz Review, January 24

http://www.unz.com/pfrost/two-paths/

 

hbd chick (2014). Medieval manorialism’s selection pressures, hbd chick, November 19

https://hbdchick.wordpress.com/2014/11/19/medieval-manorialisms-selection-pressures/

 

Hibbing, J.R., K.B. Smith, and J.R. Alford. (2014). Differences in negativity bias underlie variations in political ideology, Behavioral and Brain Sciences, 37, 297-350

http://www.geoffreywetherell.com/Hibbing%20et%20al%20paper%20and%20commentaries%20(1).pdf

 

Kanai, R., T. Feilden, C. Firth, and G. Rees. (2011). Political orientations are correlated with brain structure in young adults, Current Biology, 21, 677 - 680.

http://www.cell.com/current-biology/abstract/S0960-9822(11)00289-2

 

Keysers, C. and V. Gazzola. (2014). Dissociating the ability and propensity for empathy, Trends in Cognitive Sciences, 18, 163-166.

http://www.cell.com/trends/cognitive-sciences/pdf/S1364-6613(13)00296-9.pdf

 

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

 

Schreiber, D., Fonzo, G., Simmons, A.N., Dawes, C.T., Flagan, T., et al. (2013). Red Brain, Blue Brain: Evaluative Processes Differ in Democrats and Republicans. PLoS ONE 8(2): e52970.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0052970

 

Are liberals and conservatives differently wired?

 

Anti-UKIP protest in Edinburgh (source: Brian McNeil, Wikicommons). "Conservative" increasingly means pro-white.

 

Are liberals and conservatives differently wired? It would seem so. When brain MRIs were done on 90 young adults from University College London, it was found that self-described liberals tended to have more grey matter in the anterior cingulate cortex, whereas self-described conservatives tended to have a larger right amygdala. These results were replicated in a second sample of young adults (Kanai et al., 2011).

The amygdala is used to recognize fearful facial expressions, whereas the anterior cingulate cortex serves to monitor uncertainty and conflict (Adolphs et al., 1995; Botvinick et al., 1999; Critchley et al., 2001; Kennerley et al., 2006). Perhaps unsurprisingly, these findings were changed somewhat in the popular press. "Conservatives Big on Fear, Brain Study Finds," ran a headline in Psychology Today. The same article assured its readers that the anterior cingulate cortex "helps people cope with complexity" (Barber, 2011).

A study on 82 young American adults came to a similar conclusion. Republicans showed more activity in the right amygdala, and Democrats more activity in the left insula. Unlike the English study, the anterior cingulate cortex didn't differ between the two groups (Schreiber et al., 2013).

It would seem, then, that conservatives and liberals are neurologically different. Perhaps certain political beliefs will alter your mental makeup. Or perhaps your mental makeup will lead you to certain political beliefs. But how can that be when conservatism and liberalism have changed so much in recent times, not only ideologically but also electorate-wise? A century ago, English "conservatives" came from the upper class, the middle class, and outlying rural areas. Today, Britain's leading "conservative" party, the UKIP, is drawing more and more of its members from the urban working class—the sort of folks who routinely voted Labour not so long ago. Similar changes have taken place in the U.S. Until the 1950s, white southerners were overwhelmingly Democrats. Now, they're overwhelmingly Republicans.

Of course, the above studies are only a few years old. When we use terms like "conservative" and "liberal" we refer to what they mean today. Increasingly, both terms have an implicitly ethnic meaning. The UKIP is becoming the native British party, in opposition to a growing Afro-Asian population that votes en bloc for Labour. Meanwhile, the Republicans are becoming the party of White Americans, particularly old-stock ones, in opposition to a Democrat coalition of African, Hispanic, and Asian Americans, plus a dwindling core of ethnic whites.

So are these brain differences really ethnic differences? Neither study touches the question. The English study assures us that the participants were homogeneous:

We deliberately used a homogenous sample of the UCL student population to minimize differences in social and educational environment. The UK Higher Education Statistics Agency reports that 21.1% of UCL students come from a working-class background. This rate is relatively low compared to the national average of 34.8%. This suggests that the UCL students from which we recruited our participants disproportionately have a middle-class to upper-class background. (Kanai et al., 2011)

Yes, the students were largely middle-class, but how did they break down ethnically? Wikipedia provides a partial answer:

In 2013/14, 12,330 UCL students were from outside the UK (43% of the total number of students in that year), of whom 5,504 were from Asia, 3,679 from the European Union ex. the United Kingdom, 1,195 from North America, 516 from the Middle East, 398 from Africa, 254 from Central and South America, and 166 from Australasia (University College London, 2014)

These figures were for citizenship only. We should remember that many of the UK students would have been of non-European origin.

 

We know more about the participants in the American study. They came from the University of California, San Diego, whose student body at the time was 44% Asian, 26% Caucasian, 10% Mexican American, 10% unknown, 4% Filipino, 3% Latino/Other Spanish, and 2% African American (Anon, 2010). This ethnic breakdown mirrors the party breakdown of the participants: 60 Democrats (72.5%) and 22 Republicans (27.5%).

Affective empathy and ethnicity

In my last post, I cited a study showing that the amygdala is larger in extraordinary altruists—people who have donated one of their kidneys to a stranger. In that study, we were told that a larger amygdala is associated with greater responsiveness to fearful facial expressions, i.e., a greater willingness to help people in distress. Conversely, psychopaths have a smaller amygdala and are less responsive to fearful faces (Marsh et al., 2014).

Hmm ... That's a tad different from the spin in Psychology Today. Are liberals the ones who don't care about others? Are they ... psychopaths?

It would be more accurate to say that "liberals" come from populations whose capacity for affective empathy is lower on average and who tend to view any stranger as a potential enemy. That's most people in this world, and that's how most of the world works. I suspect the greater ability to monitor uncertainty and conflict reflects adaptation to an environment that has long been socially fragmented into clans, castes, religions, etc. This may explain why a larger anterior cingulate cortex correlated with "liberalism" in the British study (high proportion of South Asian students) but not in the American study (high proportion of East Asian students).

As for "conservatives," they largely come from Northwest Europe, where a greater capacity for affective empathy seems to reflect an environment of relatively high individualism, relatively weak kinship, and relatively frequent interactions with nonkin. This environment has prevailed west of the Hajnal Line since at least the 12th century, as shown by the longstanding characteristics of the Western European Marriage Pattern: 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. This zone of weaker kinship, with greater reliance on internal means of behavior control, may also explain why Northwest Europeans are more predisposed to guilt than to shame, whereas the reverse is generally the case elsewhere in the world (Frost, 2014).

All of this may sound counterintuitive. Doesn't the political left currently stand for autonomy theory and individualism? Doesn't it reject traditional values like kinship? In theory it does. The reality is a bit different, though. When Muslims vote Labour, it's not because they want gay marriage and teaching of gender theory in the schools. They expect something else.

The same goes for the political right. When former Labourites vote UKIP, it's not because they want lower taxes for the rich and offshoring of manufacturing jobs. They expect something else. Are they being delusional? Perhaps. But, then, are the Muslims being delusional?

 

Perhaps neither group is. Perhaps both understand what politics is really about.

 

References

 

Adolphs, R., D. Tranel, H. Damasio, and A.R. Damasio. (1995). Fear and the human amygdala, The Journal of Neuroscience, 15, 5879-5891.

http://www.emotion.caltech.edu/papers/AdolphsTranel1995Fear.pdf

 

Anon (2010). Racial breakdown of the largest California public colleges, The Huffington Post, May 4

http://www.huffingtonpost.com/2010/03/04/racial-breakdown-of-the-l_n_485577.html

 

Barber, N. (2011). Conservatives big on fear, study finds, Psychology Today, April 19

http://www.psychologytoday.com/blog/the-human-beast/201104/conservatives-big-fear-brain-study-finds

Botvinick, M., Nystrom, L.E., Fissell, K., Carter, C.S., and Cohen, J.D. (1999). Conflict monitoring versus selection-for-action in anterior cingulate cortex, Nature, 402, 179-181.

Critchley, H.D., Mathias, C.J., and Dolan, R.J. (2001). Neural activity in the human brain relating to uncertainty and arousal during anticipation, Neuron, 29, 537-545.

 

Frost, P. (2014). We are not equally empathic, Evo and Proud, November 15

http://www.evoandproud.blogspot.ca/2014/11/we-are-not-equally-empathic.html

 

Kanai, R., T. Feilden, C. Firth, and G. Rees. (2011). Political orientations are correlated with brain structure in young adults, Current Biology, 21, 677 - 680.

http://www.cell.com/current-biology/abstract/S0960-9822(11)00289-2

Kennerley, S.W., Walton, M.E., Behrens, T.E., Buckley, M.J., and Rushworth, M.F. (2006). Optimal decision making and the anterior cingulate cortex. Nat. Neurosci. 9, 940-947.

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

Schreiber, D., Fonzo, G., Simmons, A.N., Dawes, C.T., Flagan, T., et al. (2013). Red Brain, Blue Brain: Evaluative Processes Differ in Democrats and Republicans. PLoS ONE 8(2): e52970.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0052970

 

University College London. (2014). Wikipedia

http://en.wikipedia.org/wiki/University_College_London#Student_body

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.