Indicators of developmental deviance in individuals at risk for schizophrenia.

Schizophrenia is generally conceptualized as a neurodevelopmental disorder. In order to examine psychometrically-identified individuals at risk for schizophrenia in terms of indicators of developmental deviance, we examined digit ratios, nailfold plexus visibility, and dermatoglyphic features in young adults with elevated scores on the Social Anhedonia Scale. These individuals were compared to an age-matched control group. The two groups did not differ in terms of their digit ratios, though across both groups, the males had significantly lower 2D:4D ratios than the females. The socially anhedonic group had a significantly higher prevalence of nailfold plexus visibility. Males reporting excessive social anhedonia exhibited significantly lower a-b ridge counts than controls, though the two groups did not differ in terms of finger ridge counts. Study findings indicate that relationships exist between some indicators of nonspecific developmental injury and negative schizotypy, especially in males.