Answer to Question 1
Baltes identified four key features of the life-span perspective. They are as follows:
(1) Multidirectionality . Some growth may slow and some may accelerate across time in the same individual. (2) Plasticity. This means that skills are not set in stone. They can be improved or taught even in late life. (3) Historical context. Each of us is shaped by the particular historical time and culture into which we were born. (4) Multiple causation. People are influenced by biological, psychological, sociocultural, and life-cycle forces.
Answer to Question 2
By the year 2050, the shape of the population in the United States will resemble a beehive as many more individuals will be living into their 80s, 90s, and 100s. There is great concern that the cost of programs that support older Americans, such as Social Security and Medicare, will become severely strained. This situation may cause intergenerational conflict as larger numbers of people will be supported by programs fueled by smaller numbers of younger taxpayers.
The Scale of Life
Life-cycle of the Sun; sizes are not drawn to scale.
jellyfish life cycle
Jan de Heem, Still Life with Lobster.
Environmental and Lifestyle Factors of Weight Gain
Psychology and Life