Childhood amnesia refers to the inability of adults to recall events that occurred during their infancy and early childhood. Although it is generally assumed that children and adolescents also experience childhood amnesia, with limited exceptions, most empirical research on the phenomenon has focused exclusively on adults. Here, we developed a new Timeline procedure to directly compare the early memories reported by children, adolescents, and adults. Overall, the proportion of memories reported before the age of 3 years was greater for the children and adolescents relative to the adults. In addition, the single earliest memory reported by children and adolescents was at a younger age than that reported by adults. In fact, the earliest memories reported by the children and adolescents, but not the adults, were significantly younger than the traditional 3 (1/2)-year-old boundary of childhood amnesia. Regardless of the age of the rememberer, participants' early memories had the same episodic characteristics. We conclude that the boundary and the density of childhood amnesia may increase over the course of human development and that age-related changes in basic memory mechanisms make an important contribution to our understanding of the source of childhood amnesia.

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Two alternative hypotheses have been generated to account for seasonal variation in the birth weight of human infants born in industrialized countries. First, it has been hypothesized that low ambient temperature during the second trimester of gestation decreases birth weight. Second, it has been hypothesized that exposure to bright sunshine during the first trimester increases birth weight. We tested these two hypotheses to determine which, if either, accounted for seasonal variation in birth weight of full-term infants. Birth weight data, collected over a 5-year period, were analyzed as a function of peak and trough sunshine and ambient temperature. Although there was no effect of ambient temperature during any trimester on birth weight, infants whose mothers were exposed to peak sunshine during their first trimester were born significantly heavier than infants whose mothers experienced trough levels of sunshine during the same trimester. Furthermore, infants whose mothers were exposed to trough levels of sunshine during their second and third trimesters were born significantly heavier than infants whose mothers were exposed to peak levels of sunshine during the same trimesters. We hypothesize that high levels of sunshine during early gestation may increase the level of insulin-like growth factor (IGF)-1, facilitating prenatal growth.

We observed that higher levels of drinking were associated with small, yet statistically significant, differences in psychological outcomes for men and women. Our findings are of uncertain clinical significance; however, they underscore the importance of investigating a fuller range of social and personality factors that may confound the association of drinking and psychological outcomes.

Māori (Indigenous New Zealand) university graduates are role models for educational success and are critical for the social and economic wellbeing of Māori whānau (extended family) and communities. In this study, Māori graduates ( N = 626) from all eight New Zealand universities participated in the Graduate Longitudinal Study New Zealand between July and December 2011. They were asked to describe factors that they found helpful or challenging to the completion of their qualifications. Graduates described a range of external (e.g. family), institutional (e.g. academic support), and student or personal (e.g. persistence) factors. Describing the experiences of Māori graduates can provide a blueprint for future indigenous success by building an evidence base of the factors that may promote indigenous higher educational achievement in New Zealand and internationally.