<Tr> <Td> <Ul> <Li> Fertilization </Li> <Li> Childbirth </Li> <Li> Walking </Li> <Li> Language acquisition </Li> <Li> Puberty </Li> <Li> Menopause </Li> <Li> Ageing </Li> <Li> Death </Li> </Ul> </Td> </Tr> <Ul> <Li> Fertilization </Li> <Li> Childbirth </Li> <Li> Walking </Li> <Li> Language acquisition </Li> <Li> Puberty </Li> <Li> Menopause </Li> <Li> Ageing </Li> <Li> Death </Li> </Ul> <Tr> <Th> Development and psychology </Th> </Tr> <Tr> <Td> <Ul> <Li> Pre - and perinatal </Li> <Li> Infant and child </Li> <Li> Adolescent </Li> <Li> Youth </Li> <Li> Young adult </Li> <Li> Adult </Li> <Li> Maturity </Li> </Ul> </Td> </Tr>

What occurs during the differentiation phase of development