Physiognomy: Difference between revisions

* Several studies have found a link between a less acute slant to the forehead and impulsivity. Apolo et al. (2018) measured the angle of forehead slant of a largely male sample (80.2%) of traffic offenders. They found that a more heavily slanted forehead correlated positively with several psychometric measures of impulsivity.<ref>https://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-44462018000300270</ref> A follow up study by the same author (Apolo, 2020) examined a pre-screened sample of people who had been subjected to neuropsychiatric testing to exclude those with hyperactivity disorders, attentional deficits or a family history of mental illness (unlike the aforementioned study which was made up of a sample of offenders, who would be expected to be more impulsive compared to a general population sample). Apolo found multiple weak to moderate (.3-.6) significant positive correlations between the degree of forehead slant and several psychometric measures of general impulsivity, sensation-seeking and positive urgency (the tendency to engage in risky behavior more often when one is experiencing positive affect).<ref>https://www.jmedicalcasereports.org/article_html.php?did=7397&issueno=0</ref> The study also found a positive relationship between cortical thickness in certain regions of the frontal and parietal lobes and impulsive behavior. This suggests that differences in the development in different brain regions that affect behavior can be observable by examining the shape of a person's skull, a finding reminiscent of the 'pseudo-science' of phrenology, which also proposed a link between skull shape and behavior. As forehead slant is sexually dimorphic (with men generally having a more slanted forehead than women due to having a more pronounced brow ridge),<ref>https://pubmed.ncbi.nlm.nih.gov/27218032/</ref> it could be that this link is due to a more slanted forehead being reflective of higher levels of androgen exposure during key developmental periods, which has also been found to be linked to a higher risk of engaging in impulsive and violent behavior.<ref>https://www.sciencedirect.com/science/article/abs/pii/S0191886920304712</ref>