Final answer:
The truth of the statement about Schlegel and Barry's analysis cannot be verified with the provided material, but studies do show that socialization significantly influences the distribution of domestic responsibilities, with cultural variations affecting the gender roles of boys and girls.
Step-by-step explanation:
According to Schlegel and Barry's analysis, the statement that over 80% of adolescent boys and girls in traditional cultures had frequent responsibility of caring for younger siblings is not explicitly provided in the reference material provided, and therefore, cannot be determined as true or false based on the given information.
Research by Carol Ember, referenced in the material, does explore the social roles of boys and girls in different cultural settings, noting that in some cases, boys take on more traditionally 'feminine' roles when girl children are not present. Additionally, Barry Hewlett's study on the Aka of central Africa indicates that fathers can be highly affectionate and involved with childcare, challenging the assumption that men are naturally less capable in these roles.
It is clear, however, that socialization plays a significant role in the division of domestic responsibilities and the upbringing of boys and girls, with cultural variations impacting how these roles are distributed and perceived.