Welcome to the Nexus of Ethics, Psychology, Morality, Philosophy and Health Care

Welcome to the nexus of ethics, psychology, morality, technology, health care, and philosophy
Showing posts with label Heritability. Show all posts
Showing posts with label Heritability. Show all posts

Thursday, July 21, 2022

Testing heritability of moral foundations: Common pathway models support strong heritability for the five moral foundations

Zakharin, M., & Bates, T. C. (2022). 
European Journal of Personality.
https://doi.org/10.1177/08902070221103957

Abstract

Moral Foundations Theory (MFT) predicts that moral behaviour reflects at least five foundational traits, each hypothesised to be heritable. Here, we report two independent twin studies (total n = 2020), using multivariate multi-group common pathway models to test the following three predictions from the MFT: (1) The moral foundations will show significant heritability; (2) The moral foundations will each be genetically distinct and (3) The clustering of moral concerns around individualising and binding domains will show significant heritability. Supporting predictions 1 and 3, Study 1 showed evidence for significant heritability of two broad moral factors corresponding to individualising and binding domains. In Study 2, we added the second dataset, testing replication of the Study 1 model in a joint approach. This further corroborated evidence for heritable influence, showed strong influences on the individualising and binding domains (h2 = 49% and 66%, respectively) and, partially supporting prediction 2, showed foundation-specific, heritable influences on Harm/Care, Fairness/Reciprocity and Purity/Sanctity foundations. A general morality factor was required, also showing substantial genetic effects (40%). These findings indicate that moral foundations have significant genetic bases. These influenced the individual foundations themselves as well as a general concern for the individual, for the group, and overall moral concern.

From the General Discussion

Two of the highly heritable common factors in our model clearly correspond to the binding (Ingroup/ Loyalty, Authority/Respect and Sanctity/Purity) and individualising (Harm/Care and Fairness/Reciprocity) moral domains theorised by Graham et al. (2011), thereby supporting their model. At the same time, three out of five specific genetic effects were non-significant, which was unexpected. This may suggest that differences between individual foundations, for example, distinctions between Authority and Ingroup – are purely learned in origin. At this point, however, an equally plausible hypothesis is that we simply lacked the power to distinguish all the effects in the moral foundations. The sample size, but more particularly the abbreviated measures used in both datasets with reduced ability to detect facet-specific variance mean that this possibility cannot be ruled out. Future studies investigating these issues using larger, extended and even longitudinal twin designs and a wide range of measures would be valuable. In particular, it will be of value to explore whether the five distinct foundations reflect, at a genetic level, different combinations of these two major domains. Another area of interest for future research would be an analysis of distinctions between individualising measures such as Harm/Care and Fairness/Reciprocity and motivations such as compassion in other evolutionary models (e.g. Lin & Bates, 2021; Sznycer et al., 2017).

Wednesday, April 27, 2016

Are moral foundations heritable? Probably

by Jonathan Haidt
The Righteous Mind Blog
Originally posted April 11, 2016

Are moral foundation scores heritable? A new paper by Kevin Smith et al. has tested moral foundations theory in a sample of Australian twins and found that moral foundations are neither heritable nor stable over time. The authors summarized MFT fairly, and they used a research design that is appropriate for the questions they asked, but with one major flaw: They improvised an ultra-short measure of moral foundations (around 2008) that was so poor that they essentially have no measure of moral foundations at time 1. Then at time 2 (around 2010) they used a better measure, the MFQ20. As I show below, nothing can be concluded about heritability or stability from their data.

The blog post is here.

Intuitive Ethics and Political Orientations: Testing Moral Foundations as a Theory of Political Ideology

Kevin B. Smith, John R. Alford, John R. Hibbing, Nicholas G. Martin, Peter K. Hatemi
American Journal of Political Science. 
doi:10.1111/ajps.12255

Abstract

Originally developed to explain cultural variation in moral judgments, moral foundations theory (MFT) has become widely adopted as a theory of political ideology. MFT posits that political attitudes are rooted in instinctual evaluations generated by innate psychological modules evolved to solve social dilemmas. If this is correct, moral foundations must be relatively stable dispositional traits, changes in moral foundations should systematically predict consequent changes in political orientations, and, at least in part, moral foundations must be heritable. We test these hypotheses and find substantial variability in individual-level moral foundations across time, and little evidence that these changes account for changes in political attitudes. We also find little evidence that moral foundations are heritable. These findings raise questions about the future of MFT as a theory of ideology.

The article is here.