2 Interesting studies: Early Humans in SE Asia and Genetics, Relationships, and Mental Illness

Ancient Teeth Push Back Early Arrival of Humans in Southeast Asia :

New tests on two ancient teeth found in a cave in Indonesia more than 120 years ago have established that early modern humans arrived in Southeast Asia at least 20,000 years earlier than scientists previously thought, according to a new study. …

The findings push back the date of the earliest known modern human presence in tropical Southeast Asia to between 63,000 and 73,000 years ago. The new study also suggests that early modern humans could have made the crossing to Australia much earlier than the commonly accepted time frame of 60,000 to 65,000 years ago.

I would like to emphasize that nothing based on a couple of teeth is conclusive, “settled,” or “proven” science. Samples can get contaminated, machines make errors, people play tricks–in the end, we’re looking for the weight of the evidence.

I am personally of the opinion that there were (at least) two ancient human migrations into south east Asia, but only time will tell if I am correct.

Genome-wide association study of social relationship satisfaction: significant loci and correlations with psychiatric conditions, by Varun Warrier, Thomas Bourgeron, Simon Baron-Cohen:

We investigated the genetic architecture of family relationship satisfaction and friendship satisfaction in the UK Biobank. …

In the DSM-55, difficulties in social functioning is one of the criteria for diagnosing conditions such as autism, anorexia nervosa, schizophrenia, and bipolar disorder. However, little is known about the genetic architecture of social relationship satisfaction, and if social relationship dissatisfaction genetically contributes to risk for psychiatric conditions. …

We present the results of a large-scale genome-wide association study of social
relationship satisfaction in the UK Biobank measured using family relationship satisfaction and friendship satisfaction. Despite the modest phenotypic correlations, there was a significant and high genetic correlation between the two phenotypes, suggesting a similar genetic architecture between the two phenotypes.

Note: the two “phenotypes” here are “family relationship satisfaction” and “friendship satisfaction.”

We first investigated if the two phenotypes were genetically correlated with
psychiatric conditions. As predicted, most if not all psychiatric conditions had a significant negative correlation for the two phenotypes. … We observed significant negative genetic correlation between the two phenotypes and a large cross-condition psychiatric GWAS38. This underscores the importance of social relationship dissatisfaction in psychiatric conditions. …

In other words, people with mental illnesses generally don’t have a lot of friends nor get along with their families.

One notable exception is the negative genetic correlation between measures of cognition and the two phenotypes. Whilst subjective wellbeing is positively genetically correlated with measures of cognition, we identify a small but statistically significant negative correlation between measures of correlation and the two phenotypes.

Are they saying that smart people have fewer friends? Or that dumber people are happier with their friends and families? I think they are clouding this finding in intentionally obtuse language.

A recent study highlighted that people with very high IQ scores tend to report lower satisfaction with life with more frequent socialization.

Oh, I think I read that one. It’s not the socialization per se that’s the problem, but spending time away from the smart person’s intellectual activities. For example, I enjoy discussing the latest genetics findings with friends, but I don’t enjoy going on family vacations because they are a lot of work that does not involve genetics. (This is actually something my relatives complain about.)

…alleles that increase the risk for schizophrenia are in the same haplotype as
alleles that decrease friendship satisfaction. The functional consequences of this locus must be formally tested. …

Loss of function mutations in these genes lead to severe biochemical consequences, and are implicated in several neuropsychiatric conditions. For
example, de novo loss of function mutations in pLI intolerant genes confers significant risk for autism. Our results suggest that pLI > 0.9 genes contribute to psychiatric risk through both common and rare genetic variation.