Editing Developmental psychology (section)

===Old age===
{{Main|Old age}}
The [[World Health Organization]] finds "no general agreement on the age at which a person becomes old." Most [[Developed country|"developed countries"]] set the age as 65 or 70. However, in [[Developing country|developing countries]] inability to make "active contribution" to society, not chronological age, marks the beginning of old age.<ref>{{cite web | title = Definition of an older or elderly person | work = World Health Organization | url = http://www.who.int/healthinfo/survey/ageingdefnolder/en/ | access-date = 11 October 2015 }}{{dead link|date=January 2025}}</ref><ref>{{cite journal |last1=Orimo |first1=Hajime |last2=Ito |first2=Hideki |last3=Suzuki |first3=Takao |last4=Araki |first4=Atsushi |last5=Hosoi |first5=Takayuki |last6=Sawabe |first6=Motoji |title=Reviewing the definition of 'elderly' |journal=Geriatrics & Gerontology International |date=September 2006 |volume=6 |issue=3 |pages=149–158 |doi=10.1111/j.1447-0594.2006.00341.x }}</ref> According to [[Erikson's stages of psychosocial development]], old age is the stage in which individuals assess the quality of their lives.<ref name="Miller2003">{{cite book |url=https://books.google.com/books?id=rPcwuEe9MBQC&pg=PA242 |title=Encyclopedia of Human Ecology: I-Z |vauthors=Miller JR |publisher=ABC-CLIO |year=2003 |isbn=978-1-57607-852-5 |pages=242– |access-date=4 December 2012}}</ref>

Erikson labels this stage as integrity versus despair. For integrated persons, there is a sense of fulfillment in life. They have become self-aware and optimistic due to life's commitments and connection to others. While reflecting on life, people in this stage develop feelings of contentment with their experiences. If a person falls into despair, they are often disappointed about failures or missed chances in life. They may feel that the time left in life is an insufficient amount to turn things around.<ref>{{cite journal |last1=Hearn |first1=Simon |last2=Saulnier |first2=Gary |last3=Strayer |first3=Janet |last4=Glenham |first4=Margarete |last5=Koopman |first5=Ray |last6=Marcia |first6=James E. |title=Between Integrity and Despair: Toward Construct Validation of Erikson's Eighth Stage |journal=Journal of Adult Development |date=March 2012 |volume=19 |issue=1 |pages=1–20 |doi=10.1007/s10804-011-9126-y }}</ref>

Physically, older people experience a decline in muscular strength, reaction time, stamina, hearing, distance perception, and the sense of smell.<ref name="Deary2011">{{cite journal | vauthors = Deary IJ, Johnson W, Gow AJ, Pattie A, Brett CE, Bates TC, Starr JM | title = Losing one's grip: a bivariate growth curve model of grip strength and nonverbal reasoning from age 79 to 87 years in the Lothian Birth Cohort 1921 | journal = The Journals of Gerontology. Series B, Psychological Sciences and Social Sciences | volume = 66 | issue = 6 | pages = 699–707 | date = November 2011 | pmid = 21743039 | doi = 10.1093/geronb/gbr059 | doi-access = free | hdl = 20.500.11820/a59dc7c1-af60-4f02-a8be-37987b26f9a4 | hdl-access = free }}</ref> They also are more susceptible to diseases such as cancer and pneumonia due to a weakened immune system.<ref>{{cite journal |last1=Larbi |first1=Anis |last2=Rymkiewicz |first2=Paulina |last3=Vasudev |first3=Anusha |last4=Low |first4=Ivy |last5=Shadan |first5=Nurhidaya Binte |last6=Mustafah |first6=Seri |last7=Ayyadhury |first7=Shamini |last8=Fulop |first8=Tamas |title=The Immune System in the Elderly: A Fair Fight Against Diseases? |journal=Aging Health |date=February 2013 |volume=9 |issue=1 |pages=35–47 |doi=10.2217/ahe.12.78 }}</ref> Programs aimed at balance, muscle strength, and mobility have been shown to reduce disability among mildly (but not more severely) disabled elderly.<ref name="Gill2002">{{cite journal | vauthors = Gill TM, Baker DI, Gottschalk M, Peduzzi PN, Allore H, Byers A | title = A program to prevent functional decline in physically frail, elderly persons who live at home | journal = The New England Journal of Medicine | volume = 347 | issue = 14 | pages = 1068–1074 | date = October 2002 | pmid = 12362007 | doi = 10.1056/NEJMoa020423 | doi-access = free }}</ref>

Sexual expression depends in large part upon the emotional and physical health of the individual. Many older adults continue to be sexually active and satisfied with their sexual activity.<ref>{{cite book| vauthors = Cavanaugh JC, Blanchard-Fields F | author-link2=Fredda Blanchard-Fields | name-list-style = vanc |title=Adult development and aging|year=2009|publisher=Wadsworth/Cengage Learning|location=Australia|isbn=978-0-495-60174-6|pages=89–90|edition=6th}}</ref>

Mental [[wikt:disintegration|disintegration]] may also occur, leading to [[dementia]] or ailments such as [[Alzheimer's disease]]. The average age of onset for dementia in males is 78.8 and 81.9 for women.<ref>{{cite journal | vauthors = Brinks R, Landwehr S, Waldeyer R | title = Age of onset in chronic diseases: new method and application to dementia in Germany | journal = Population Health Metrics | volume = 11 | issue = 1 | pages = 6 | year = 2013 | pmid = 23638981 | pmc = 3665482 | doi = 10.1186/1478-7954-11-6 | doi-access = free }}</ref> It is generally believed that [[crystallized intelligence]] increases up to old age, while [[fluid intelligence]] decreases with age.<ref>[https://web.archive.org/web/20000525173324/http://www.webster.edu/~woolflm/cognitions.html Woolf, Linda M. "Theoretical Perspectives Relevant to Developmental Psychology", Webster, 1998.]  Retrieved on 2012-03-16.</ref> Whether or not normal intelligence increases or decreases with age depends on the measure and study. [[Longitudinal study|Longitudinal studies]] show that perceptual speed, inductive reasoning, and spatial orientation decline.<ref name="What Can We Learn From Longitudinal">{{cite journal | vauthors = Schaie KW | title = What Can We Learn From Longitudinal Studies of Adult Development? | journal = Research in Human Development | volume = 2 | issue = 3 | pages = 133–158 | year = 2005 | pmid = 16467912 | pmc = 1350981 | doi = 10.1207/s15427617rhd0203_4 }}</ref> An article on adult cognitive development reports that [[Cross-sectional study|cross-sectional studies]] show that "some abilities remained stable into early old age".<ref name="What Can We Learn From Longitudinal"/>