Minor physical anomalies, intelligence, and cognitive decline

Background/Study Context: Minor physical anomalies are thought to be markers of development and increased frequency of such anomalies has been linked to lower levels of intelligence. Here the authors examine a finger curvature anomaly, and evaluate its potential as a marker of the causes of cognitive aging.

Methods: Participants were members of the Lothian Birth Cohort 1921 (LBC 1921). Intelligence was assessed at ages 11, 79, and 87. In wave 3, at age 87, 192 participants had both hands scanned with a high-resolution flatbed scanner and the curvature of the fifth digit was measured with image editing software. Multiple regression analyses were conducted to examine the proportion of unique variance in cognitive decline that could be explained by the finger curvature anomaly.

Results: Finger curvature was significantly associated with cognitive decline across the life span (beta=-.19, p=.02). Curvature was not associated with intelligence at age 11 or with decline during the period age 79 to age 87.

Conclusion: Continuously varying minor physical anomalies may accumulate to provide a marker of factors impacting life span cognitive change. Curvature anomalies may reflect the common causes underlying cognitive and physical decline.