Introduction to Adulthood

Adulthood can be described as the period in every human life in which they are under complete maturity of physical and intellectual well-being. The adult stage is the period of every human being when parental control is lost and everyone is assigned their responsibilities. In legal terms, the adulthood stage is the time in human life when they reach the major age which means they become self-reliant and decisive. Mature adulthood also indicates the development of psychological and sexual maturity. Several different events take place during the transition period of a human being from childhood period to adulthood period.

What is Adulthood?

To define adulthood biologically, it is usually determined by the onset of secondary sex characteristics in both male and females. In males the secondary sex characteristics include behaviour like ejaculation, features like facial hairs, deepening of voice and growth of pubic hairs are seen. In females, the secondary characteristics of adulthood include features like the development of breasts, starting of menstruation. During earlier days, the adult stage marked the onset of time for individuals to go out and work and support their families. Since in the olden times' education or school was not given much importance, children soon after reaching the adulthood stage could work independently without any prior experience.

To describe what is adulthood legally, the adult stage can be defined as the major age of self-reliance and responsibilities.

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Adulthood Age Range

The adulthood age range is commonly considered to begin at the age of 20 or 21 years. Our middle age starts at the age of 40 which is then followed by our old age which commences at the age of 60. The age for the commencement of legal adulthood might vary from one country to another. Usually, the legal adult stage starts at the age of 18.

Adulthood can also be further classified as:

  1. The Early Adulthood Stage: This adulthood stage lies in the adulthood age range of 22-34.

  2. The Early Middle Age: This adulthood stage lies in the adulthood age range of 35-44.

  3. The Late Middle Age: This adulthood stage lies in the adulthood age range of 45-64.

  4. Late Adulthood: This adulthood stage lies in the adulthood age range of 65 and above.

Adulthood and Related Changes in the Body

The adult stage is marked by the slow decline of body functions in the later period. Although we find that the muscles increase till the middle of 20s and the mass of the skeleton increases till the age of 30s, soon there is a decrease in growth and cellular and nervous activity. Sexual activity might also be hampered in both males and females. A decline in the nervous activity of older adults is marked by changes in the electrical activity of the brain. Older adults might face changes in their learning ability, their movement and also can face impaired visual sensation and other physical problems. The older part of mature adulthood slowly leads an individual to age.

Did You Know?

  1. Although the learning capacity of young adults, that is their trait to organize newly gained information, is much faster than the old adults, the capacity of retention of information in general that is to accumulate knowledge is much more in old adults.

  2. Typically the age for attaining adulthood is 18. However, adulthood also depends on the psychological behaviour of an individual. A person even after attaining biological maturity can behave like a child. Again a child with no biological maturity can behave like an adult. 


Adulthood is thus marked by several physiological and psychological changes in the human body. It is the phase when an individual learns to make decisions and live an independent life. Most of the individuals start families of their own during this time. This is the time in the life of every individual when a single action or decision can have a huge impact on his/her life and society at large.

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