This study confirms the association between exposure to the humanities and both a higher level of students' positive qualities and a lower level of adverse traits. These findings may carry implications for medical school recruitment and curriculum design. "[Science and humanities are] twin berries on one stem, grievous damage has been done to both in regarding [them]... in any other light than complemental." (William Osler, Br Med J. 1919;2:1-7).

Species level right-handedness is often considered to be unique to humans. Handedness is held to be interrelated to our language ability and has been used as a means of tracing the evolution of language. Here we examine handedness in 3 captive groups of bonobos (Pan paniscus) comprising 22 individuals. We found no evidence for species level handedness. Conclusions that can be drawn from these findings are: (1) species level handedness evolved after the divergence of the Pan and Homo lineages; (2) inconsistent preferences may represent precursors to human handedness, and (3) Pan may have language abilities but these cannot be measured using handedness.

Species-level right handedness is frequently presented as a marker of human uniqueness. Handedness also has implications for the evolution of language and cognition. In this study, we examined handedness in 22 captive gorillas (Gorilla gorilla) across a range of behaviours that were part of their daily routine. Ten individuals showed no preferences for any of the behaviours performed, and the majority of the remaining individuals showed a preference for only one behaviour. These results lend support to the theory that species-level handedness is unique to humans. It is hoped that these results will contribute to investigations into the evolution of handedness, which can ultimately be used to further our understanding of the evolution of human language and cognition.

Background: Although autism spectrum disorder (ASD) is heritable, the mechanisms through which genes contribute to symptom emergence remain unclear. Investigating candidate intermediate phenotypes such as the pupillary light reflex (PLR) prospectively from early in development could bridge genotype and behavioural phenotype. Methods: Using eye tracking, we longitudinally measured the PLR at 9, 14 and 24 months in a sample of infants (N = 264) enriched for a family history of ASD; 27 infants received an ASD diagnosis at 3 years. We examined the 9-to 24-month developmental trajectories of PLR constriction latency (onset; ms) and amplitude (%) and explored their relation to categorical 3-year ASD outcome, polygenic liability for ASD and dimensional 3-year social affect (SA) and repetitive/restrictive behaviour (RRB) traits. Polygenic scores for ASD (PGS ASD ) were calculated for 190 infants. Results: While infants showed a decrease in latency between 9 and 14 months, higher PGS ASD was associated with a smaller decrease in latency in the first year (b = À.16, 95% CI = À0.31, À0.002); infants with later ASD showed a significantly steeper decrease in latency (a putative 'catch-up') between 14 and 24 months relative to those with other outcomes (typical: b = .54, 95% CI = 0.08, 0.99; other: b = .53, 95% CI = 0.02, 1.04). Latency development did not associate with later dimensional variation in ASD-related traits. In contrast, change in amplitude was not related to categorical ASD or genetics, but decreasing 9-to 14-month amplitude was associated with higher SA (b = .08, 95% CI = 0.01, 0.14) and RRB (b = .05, 95% CI = 0.004, 0.11) traits. Conclusions: These findings corroborate PLR development as possible intermediate phenotypes being linked to both genetic liability and phenotypic outcomes. Future work should incorporate alternative measures (e.g. functionally informed structural and genetic measures) to test whether distinct neural mechanisms underpin PLR alterations.

No abstract