social-cultural factors, but still cannot be controlled or easily changed by these factors. Therefore, it is suggested that temperament should be kept as an independent concept for further studies and not be conflated with personality. Moreover, temperament refers to dynamical features of behavior (energetic, tempo, sensitivity and emotionality-related), whereas personality is to be considered a psycho-social construct comprising the content characteristics of human behavior (such as values, attitudes, habits, preferences, personal history, self-image). Temperament researchers point out that the lack of attention to extant temperament research by the developers of the Big Five model led to an overlap between its dimensions and dimensions described in multiple temperament models much earlier. For example, neuroticism reflects the traditional temperament dimension of emotionality, extraversion the temperament dimension of "energy" or "activity", and openness to experience the temperament dimension of sensation-seeking. Heritability A 1996 behavioural genetics study of twins suggested that heritability and environmental factors both influence all five factors to the same degree. Among four twin studies examined in 2003, the mean percentage for heritability was calculated for each personality and it was concluded that heritability influenced the five factors broadly. The self-report measures were as follows: openness to experience was estimated to have a 57% genetic influence, extraversion 54%, conscientiousness 49%, neuroticism 48%, and agreeableness 42%. Non-humans The Big Five personality traits have been assessed in some non-human species but methodology is debatable. In one series of studies, human ratings of chimpanzees using the Hominoid Personality Questionnaire, revealed factors of extraversion, conscientiousness and agreeableness – as well as an additional factor of dominance – across hundreds of chimpanzees in zoological parks, a large naturalistic sanctuary, and a research laboratory. Neuroticism and openness factors were found in an original zoo sample, but were not replicated in a new zoo sample or in other settings (perhaps reflecting the design of the CPQ). A study review found that markers for the three dimensions extraversion, neuroticism, and agreeableness were found most consistently across different species, followed by openness; only chimpanzees showed markers for conscientious behavior. A study completed in 2020 concluded that dolphins have some similar personality traits to humans. Both are large brained intelligent animals but have evolved separately for millions of years. Development during childhood and adolescence Research on the Big Five, and personality in general, has focused primarily on individual differences in adulthood, rather than in childhood and adolescence, and often include temperament