40 to 60 years of age

Decline or increase in intellectual ability

Increase in crystallized intelligence

Fluid intelligence begin to decline
In middle adulthood, some experience a decline in their intellectual abilities while others experience an increase in these abilities. The acquired store of skills, information and strategy, also known as crystallized information increases (Boyd, Bee, & Johnson, (2014). The ability to deal with new situations, also known as fluid intelligence, begin to decline.

Late adulthood

Beyond 60 years of age

Declined speed of processing information 

Selective attention

Divided attention
In late adulthood, there is a decline in the speed of processing information because of the decline in the brain and CNS functioning. There is also a selective attention causing reduced performance in areas where they are not competent. These adults also have divided attention especially when handling difficult tasks (Broderick & Blewitt, 2015)

Middle Adulthood
Bone loss in female
Decline in muscle strength and stamina
Thin and grey hair and wrinkled skin
Surfacing of chronic health problems
The female in middle adulthood may experience bone loss as early as 35 years. Men may nit experience bone loss until the age or 65. Muscle strength and stamina may  begin to decrease at this stage. Hair may also start turning gray and thin (Sigelman & Rider, 2014). Wrinkles start appearing on the skin. Chronic health issues such as diabetes, heat disease, and hypertension may surface at this stage.


Late Adulthood
Reduced heart functioning
More noticeable wrinkles and age spots
Hair becomes thinner and greyer
Yellowing of the teeth
In late adulthood, there is reduced functioning of the heart caused by the reduced capacity of the heart to pump blood through the circulatory system. This is caused by the hardening of the arteries and shrinking of the blood vessels. Wrinkles and age spots tend to be more noticeable. The skin also loses its elasticity. The hair becomes thinner and greyer and there is yellowing of the teeth (Broderick, P. C., & Blewitt, 2015)

Life span reduces because of increase in chronic diseases

Cancer is a major cause of death in this stage
In the middle adulthood, the lifespan reduces because of threats from diseases. Most of these adults die of cancer than of chronic diseases (Broderick & Blewitt, 2015).
Late Adulthood
Very short life span because of diseases and low immunity
Tissues start wearing off and are rarely replaced
In late adulthood, the chronic diseases are the leading causes of death. The life span is very short and most of the adults die in this stage. There is wearing off of tissues that are not replaced leading to decreased body wellness and thus death (Zimmermann & Iwanski, 2014).