I had previously posted about a study (American Journal of Human Biology, 16(1): 31 - 42) which found a month-of-birth effect in height and weight for Polish school children. This new study indicates that psychological makeup is also affected by the season in which one is born.
Personality and Individual Differences (Article in Press)
Season of birth variation in sensation seeking in an adult population
Carol Joinson et al.
Previous research has identified a relationship between season of birth and level of novelty seeking (Chotai, Lundberg, & Adolfsson, 2003). The current study investigates whether level of sensation seeking is also related to birth season in individuals from the Northern Hemisphere. Participants were 448 students of The Open University, UK (125 males, 323 females, age range 20–69 years, mean = 39.2, SD = 9.8). The Sensation Seeking Scale V and a demographic questionnaire including month of birth were completed by participants either on the World-Wide Web (n = 284) or on paper (n = 164). A significant interaction of age and season of birth on level of sensation seeking was found, similar to previous findings for novelty seeking. Individuals aged 20–45 years born during October to March had a higher level of sensation seeking than those of the same age born in the other six months, while the opposite association was found for individuals aged 46–69 years. Results suggest an age-related difference in level of sensation seeking between individuals born during different seasons. Possible reasons for the seasonal difference are discussed, including development of the sensation seeking trait across the lifespan in relation to dopamine turnover.