A 2016 British Journal of Psychology paper by SMU Professor of Psychology Norman Li and Satoshi Kanazawa of the London School of Economics reanalysed a national US dataset of 15,197 adults aged 18–28. The study found that frequent socialising with friends was positively associated with life satisfaction for most young adults, but the positive association weakened as verbal-intelligence scores rose. Among higher-scoring respondents, the association was reversed, with frequent socialisers reporting slightly lower predicted life satisfaction. The interaction was statistically significant but tiny, with an estimated standardised effect size of minus 0.03. The study measured socialising by how often respondents hung out with friends or talked with them on the telephone for more than five minutes.
Read about the article here.