Adolescence is a time when maturing individuals have extreme and inconsistent feelings during this life stage. Csikszentmihalyi and Lason carried out a study that resulted in finding a lot of students having extreme mood swings in less than an hour that made this theory more valid. Although, the evidence did not show any background information or any hard evidence that validates Hall’s theory. Personal circumstances and background history should be taken into account before stating such theory.
On the other hand, Erikson believed that each stage of Lifespan development has two conflicting personality outcomes, a positive and a negative. Erikson believed that one of the biggest challenges that adolescents go through is a personality crisis. The start of puberty makes adolescents concerned where they stand in the community. Erikson stated that not being able to establish a personal identity can cause role confusion which according to Erikson can affect several aspects of life such as intimacy, not being able to plan for the future, difficulty in dealing one issue at a time and worst, may develop a negative identity.
Erikson believed that adolescents need to establish a secured personal identity to be able to strive and be able to handle more difficult situations throughout adulthood. However, this theory was based on western cultures and many other cultures might behave and take adolescence differently instead of it being a stage of ‘Personality Crisis’. Adolescence is a crucial part because we need to develop a positive identity to adulthood. Erikson also believed that after adolescents have been able to create their personality, the next aspect of life adults look for is establishing intimacy and forming close relationship with others ‘without losing oneself in the process’. 
Erikson stated that intimacy is impossible if one person have not established identity, and that it is impossible to love someone if an individual does not even know it’s own identity and that if adults fail to form intimacy with other individuals, intimacy will turn into isolation. Failure to establish intimacy is also failing to establish generativity that can cause people to be occupied by their needs and treat themselves as their own child. Erikson called this stagnation. Erikson therefore concluded that in order to be successful and happy in adulthood, one must be able to establish a strong and solid identity in adolescence.
Psychologists have evaluated Erikson’s theory as inaccurate because a lot has changed since it has been created; Individuals tend to engage in co-habiting relationships now unlike before. Gilligan also pointed out that psychological changes for women are different but Erikson’s theory was meant to be universal. Contrary to Erikson’s Life stages, Levinson believed that adulthood go through its individual stages and called it ‘Seasons of a man’s life’. Levinson collected data shortly after the great depression ended from men who are at the adulthood phase.
Levinson stated that adulthood is divided into two concepts: The stable and the transitional period. Levinson then said that adolescents leave adolescence to make preliminary choices for adulthood and then establish relationships, lifestyle and occupation choices. Levinson believes that there is a transition at age 30 and it can be moderate or severe. Levinson then stated that settling down happens when adults reach their mid 30’s and after establishing a family, adults then goes into midlife transition that eventually prepares adult for entering middle adulthood.
Levinson outlined that changes happen at certain age in adults particularly men go through this changes. Critics find that there is irregularity in Levinson’s theory. Men who were interviewed and used to collect data haven’t reached 45 yet. Also, the data were collected after great depression and critics have found that these men came from stable families, had realistic goals and grew in an expanding economy. Also, this theory is ‘old-fashioned’ because nowadays, individuals don’t follow this kind of transition.
Hopson and Adams (1978) then created a model to elaborate personal responses to huge transitions in adulthood. Hopson Identified 7 major transitions: Immobilization, minimization, depression, acceptance, testing, seeking meaning and internalization. The identification of this transitions help professionals come up to a better understanding of people but these transitions may not happen all the time. Individuals go through this transition to be able to understand why these things happen. It is more of a discovery and analysis rather than a transition.
Although a lot of people go through this transitions, some people might differ in handling crises, and individuals’ circumstances, characteristics and experiences may vary that in return can affect on how they handle crisis. Middle Adulthood is also see as a preparation for Late Adulthood. Kastenbaum believes that age differ in chronological, biological, subjective and functional age. According to Kastenbaum, chronological age is your age when you were born, while biological focuses on physical appearance as to how old do people think a person is and how the individual sees their age. Subjective on the other hand focuses on how an individual feels its age is, which might also relate to the maturity of the person while functionality age refers to the capacity of an individual and what the individual can do.
Kastenbaum’s theory is proven to be realistic and true as a lot of people feels younger than their age and some people are still immature despite what people expect in their actions when considering their age. Elderly people are often seen as incapable because of their age but other people do not see their capabilities underneath their age. They are often only seen as their chronological and not seen beyond functional and subjective age.
On the other hand, Cummings and Henry believed that when an individual reaches its late adulthood, they start to disengage with people around them. Disengagement is when an individual separates or disconnects itself from society. Social Disengagement starts to occur when an individual goes through retirement. That means individuals get less interaction from society. Elderly people also get a lot of discrimination and stereotyping that makes them separate themselves from the community. However, Havighurst and Maddox believed that it is re-engagement (activity) rather than disengagement. Contrary to the social disengagement theory, Havighurst and Maddox believed that withdrawal from society is not mutual and is in fact against elderly people’s wishes.