Physical development PDF

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Stages of physical development...

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Physical development Adolescence Physical development in adolescence centres on the physical and hormonal changes that take place in puberty. Puberty refers to the period of rapid physical maturation involving hormonal and bodily changes that occur primarily during early adolescence (Santrock, 2007). Puberty begins with hormonal increases, which cause a range of bodily changes that signify sexual maturation and gender differentiation. These changes result in primary sexual characteristics, which are directly related to reproduction, and secondary sexual characteristics, which distinguish the sexes without being related to production (e.g. facial hair). These changes include a growth spurt in height and weight, which lasts about four and a half years (Papalia, Olds & Feldman, 2010), and which peaks at eleven and a half years for girls and thirteen and a half years for boys (Santrock, 2007). there are many factors that impact on the onset of puberty, such as nutrition, health, heredity and body mass (Santrock, 2007). This means that the onset of puberty may vary greatly from person to person, and across different cultures. Notable physical changes in puberty include the following: • Girls’ ovaries enlarge, and all parts of the reproductive system become more developed. Owing to these changes, the menstrual cycle begins for young women (menarche). 4.1 RITES OF PASSAGE Most cultures have rituals linked to the transition from childhood to adulthood. In many indigenous South African cultures, a circumcision ritual carried out in groups and in a remote area (in the bush) has been traditional for late-adolescent males. Ramphele (2002, p. 57) details an account of a Xhosa initiation ritual as experienced by one of the young men she interviewed, highlighting the centrality of ‘discipline and fortitude in the face of physical and emotional strain’. There are many other examples of puberty rites across the globe. Robinson (2002) details some examples: • Navajo young men make a solo journey into the mountains to attain their manhood. • Australian aboriginal adolescents are given tattoos in late puberty as preparation for adulthood, and the transition is viewed through the metaphor of the death of childhood and the rebirth of adulthood. • Girls of the Arapesh tribe in New Guinea stay in menstrual huts in early puberty for six days without food or water. • Religious families in North America celebrate a teenager’s Confirmation (in Christian families) or a Barmitzvah (in Jewish families).

• Boys’ testicles, penis, scrotum, prostate gland and seminal vessels are further developed, along with the beginning of sperm production (spermarche). • Body hair increases, primarily pubic and underarm hair, but also facial and upper-torso hair, especially in boys. • Girls develop breasts. • Voices deepen. • Skin textures change, which may result in skin infections such as acne. The body changes in adolescence clearly also have many psychological consequences. Adolescents often become preoccupied with their bodies (Santrock, 2007). This focus on the body differs according to gender, with pressure on males to develop their bodies, while young women are expected to conform to the widespread media image of slimnes). It is not surprising, then, that the eating disorders anorexia nervosa and bulimia nervosa most frequently begin in adolescence. Much of the psychological literature on these disorders highlights the significance of the social pressures on girls to achieve the slender ideal image, as well as the socio-psychological meanings of developing into adult women (see, for example, the seminal works of Bruch, 1974; Orbach, 1978). Although it has been argued that eating disorders are only present in affluent societies or middle-class families, there is growing evidence that South African youth, particularly adolescent girls, in all communities are at risk (Jordaan, 2014). For example, a recent study found that the prevalence of abnormal eating attitudes is equally common in South African schoolgirls from different ethnic backgrounds (Mould, Grobler, Odendaal & De Jager, 2011). SUMMARY • Physical development in adolescence starts with the hormonal and bodily changes of puberty. • Puberty leads to the development of primary and secondary sexual characteristics, and includes a growth spurt. • In many cultures, puberty is celebrated with rites of passage. • The onset of puberty is affected by nutrition, health, heredity and body mass, as well as individual differences. • Physical changes in adolescence often have psychological consequences. • The focus on the body may lead to eating disorders, primarily in girls. Early adulthood With regard to physical development, early adulthood is generally considered to constitute the prime of life. For example, at approximately 25 to 30 years of age, physical growth as well as muscular strength and manual dexterity reach a peak (Santrock, 2007). With regard to

overall health, the early years of adulthood are generally also considered to be one of the more problem-free periods in the human life cycle. However, this period also announces the first visible signs of aging. For example, because of hormonal changes and a reduced flow of blood to the skin, hair may already grow less abundantly from the late 20s onwards. Additionally, as the skin begins to lose its elasticity, facial wrinkles may start making their appearance at this stage (Staehelin, 2005). 4.2 THE INTERPLAY OF CULTURE AND BIOLOGY IN PUBERTY Puberty is usually presented as a biological and universal fact of change that heralds adolescence. However, biology is not something unrelated to culture. Rather, it is becoming more evident that the social world has a complex impact on humans’ biological and physiological lives. Reports of the effect of hormones used on animals in the production of meat represents one of the most frightening indicators of the way in which biology and culture are interwoven in the experience of puberty. In Puerto Rica in the 1980s, there were reports of girls as young as the age of four developing breasts, and beginning to menstruate (Henriques, Holloway, Urwin, Venn & Walkerdine, 1984). The acceleration of sexual maturation was believed to be the result of the use of oestrogen in the feed of chickens, and these chickens formed part of the staple diet of this group of Puerto Ricans. Henriques et al. (1984, p. 21) comment that the ‘effect of these biological changes is utter confusion of the children, their peers and adults regarding appropriate behaviour and expectations’. A further example of the way in which puberty is affected by environmental context is provided by cross-cultural and historical differences in the onset age of puberty. Papalia et al. (2010) note that there has been a significant drop in the average age of menarche in the last 100 years, primarily in first-world countries. Health risks Although globally early adulthood is generally considered the period when the individual is least likely to experience health problems, in South Africa, young adults are at risk both from violence and from disease. In this age group, individuals are most at risk of death or injury through almost all forms of violence, including violent assault and suicide, and motor vehicle collisions (Donson, 2009). Donson (2009) also reports that violence is the leading cause of non-natural death for 15- to 24-year-olds (44.8 per cent), 25- to 34-year-olds (41.5 per cent) and 35- to 44-year-olds (33.1 per cent). In Gauteng in 2011, violence peaked as a cause of non-natural death in the 24- to 29-year-old group with the male–female ratio being close to 6:1 (Medical Research Council, 2013). According to Miedzian (in Berger, 1994), the gendered patterns of injury and death due to violence are the result of a complex interaction between a range of biosocial factors. These factors include the higher levels of testosterone and drug abuse found among males, as well as early socialisation (Sell, Hone & Pound, 2012). This will be discussed in more detail later in this chapter. HIV/AIDS and tuberculosis are other major health problems currently facing young adults in South Africa. Tuberculosis is the current leading cause of death in South Africa (Statistics South Africa, 2014a), being responsible for 10.7 per cent of deaths in 2011. In terms of HIV, in South Africa in 2012, there was a gender difference in prevalence with 9.9 per cent of

males infected and 14.4 per cent of females. This is partly because of physiological factors and partly because of social dynamics, for example the tendency for older men to be ‘sugar daddies’ to girls in their teens (Wyrod et al., 2011). Overall, HIV prevalence peaks between 30 and 39 years (about 30 per cent), but in the 20- to 24-year-olds, prevalence for females is 17.4 per cent compared to 5.1 per cent for males. As will become clearer later in this chapter, the alarming spread of this pandemic has had a significant impact on the manner in which many young South Africans embark on two of the more crucial life tasks of early adulthood, namely establishing an intimate relationship with a life-partner and parenting. Middle adulthood In terms of chronological age, middle adulthood is traditionally reported to extend from roughly the age of 40 years to roughly the age of 60 years, with a range of physical, biological and social cues or indicators generally marking its onset. As noted in the introduction to this part, these age ranges depend on the life expectancy of a country’s population. Some of these indicators are considered below. Middle adulthood is generally characterised by an increasingly perceptible decline in physical attributes and functioning (Helson & Soto, 2005). This includes a decrease in muscle size, the gradual shrinkage and stiffening of the skeleton, an increase in body fat retention, and a decline in dexterity, flexibility, and sensory and perceptual abilities (Sadock & Sadock, 2011). For example, a decline in visual capacities is prominent from about the age of 40, while taste, smell and sensitivity to pain and temperature generally decline from about 45 years (Santrock, 2007). Additionally, during this period there is also a decline in the functioning of the digestive system, and a decrease in the flow of blood to the brain. Women reach menopause (which refers to the end of menstruation, and, consequently, the capacity to bear children) and males experience a decline in sexual responsiveness (Staehelin, 2005). The physical experience of middle (and late) adulthood generally occurs earlier among lower income, unskilled workers than among higher income professionals. This is largely a result of the fact that lower income groups, compared to their higher income counterparts, are generally more frequently exposed to health risks (such as working with industrial chemicals, long hours of strenuous labour, inadequate health facilities and stress) that hasten the aging process (Mathers, Sadana, Salomon, Murray & Lopez, 2001). While middle adulthood is the stage when the first signs of significant physical decline appear, many developmental experts believe that regular exercise and a good diet can slow the aging process substantially, and allow the individual to continue to function with vitality and a sense of well-being (Staehelin, 2005). However, in a country and a world where the gap between the rich and the poor is getting bigger (World Bank, 2014), we may well ask how many people will be privileged enough to enhance their quality of life in this way. Health risks During middle adulthood, the individual becomes increasingly susceptible to the risk of various ailments, such as cardiovascular diseases (which include cardiac disorders,

arteriosclerosis and hypertension), various forms of cancer, arthritis and respiratory diseases (Staehelin, 2005). This increased susceptibility to illness and disease during this stage of development is largely a result of the increasing degeneration of the body. Nonetheless, research evidence shows that people’s living conditions and lifestyles have a significant influence on their health. For example, heavy smoking and drinking have been implicated in various cardiovascular diseases (Staehelin, 2005). Furthermore, it appears that stress associated with certain lifestyles (such as hyper-competitiveness and social isolation) and living conditions (such as unemployment, and living in poverty-stricken and violent communities) contribute significantly to the health problems of middle adulthood, particularly to cardiovascular diseases and depression (Burney et al., 2013). However, the way in which individuals perceive and respond to the stressful events with which they are confronted also influences the impact on their health. For example, individuals who perceive a potentially stressful event as a challenge that they can deal with, are much less likely than others to be adversely affected by it (Faure & Loxton, 2003). Late adulthood/old age Developmental psychologists have traditionally used the age of 60 years as a marker for the onset of late adulthood. However, as populations become increasingly long-lived, it is likely that this age range may move upwards in future. The commencement of late adulthood coincides with senescence – the increasing decline of all the body’s systems, including the cardiovascular, respiratory, endocrine and immune systems (Sadock & Sadock, 2011). However, the actual rate of aging may vary greatly among individuals. Furthermore, the belief that old age is always associated with profound intellectual and physical infirmity is a myth. The majority of older people retain most of their physical and cognitive abilities (Sadock & Sadock, 2011). The general increase of living standards and medical technology has led to an increase in longevity in many societies and, therefore, a significant number of older persons. In some countries like the UK, the retirement age is steadily rising. This increasing number of older people is a challenge for the economically active section of the population to support. However, for many low-income countries, the situation is very different. For example, while the average life span in the US is 79.56 years, for South Africans it is 49.56 years (Central Intelligence Agency, n.d.). According to Statistics South Africa (2014a), life expectancy in South Africa for people born in 2014 is 59.1 years for males and 63.1 years for females. Of course, it is not just average life expectancy that differs between societies; it is also the number of years of full health that the average person enjoys. Health-adjusted life expectancy (HALE) is a measure developed by the World Health Organization to determine the average number of years that specific populations are expected to live in full health. Coutsoukis (n.d.) reports that in 2014, the HALE for Americans was 70.4 years, while for South Africans it was 39.8 years. These differences between the average life spans and the HALEs of the populations of low-income and high-income countries are largely a result of the differences in their standards of living. With senescence, there is a decline in sensory and psychomotor abilities, although with a great deal of individual variation (Sadock & Sadock, 2011; Staehelin, 2005). The loss of vision and hearing are common, and may have particularly serious psychological impacts since they hinder a range of daily living and social activities, and therefore the individual’s

independence (Margrain & Bolton, 2005). There may also be a sharp drop in sensitivity to a range of flavours and smells, with older people often complaining that food is less tasty and, consequently, eating less. Furthermore, older people experience a decline in strength, muscular coordination and reaction times (Staehelin, 2005), resulting in higher proportions of home and traffic accidents. With senescence, there is a shortening of the spinal column, a consequent decrease in height, and an increased vulnerability to osteoporosis, especially among women. Generally, the organs, especially the heart, become less efficient. There is also an increasing decline in the immune system, with greater susceptibility to infectious illnesses. For both men and women, there is an increased decline in sexual function and responsiveness (Staehelin, 2005). Health risks Given the longer HALE in the US, most individuals in the period of late adulthood are likely to enjoy reasonable health, despite the onset of some physical decline. However, in South Africa, the experience of health may vary widely, depending on socio-economic status, gender and whether people live in an urban or rural location (World Health Organization, n.d.). As suggested in the previous section, many South Africans will not even reach late adulthood. Those who do may experience a decline in their health owing to injuries and infections, and an increase of non-communicable diseases like diabetes and hypertension. Generally, the increased susceptibility to illness during this stage of development is largely a result of the progressive degeneration of the body. In South Africa, however, many older people who have experienced a lifetime of poor diet, arduous physical labour, multiple pregnancies and inadequate reproductive health care have an even greater susceptibility to ill health (Burney et al., 2013). In this age group, major causes of illness, disability and death are strokes, tuberculosis (TB), heart disease, diabetes and cancer (Bradshaw, Schneider, Laubscher & Nojilana, 2002). About 90 per cent of older adults have considerable annual medical expenses, with few having any medical insurance. Many older adults rely upon the assistance of their family and the state to meet rising medical expenses. SUMMARY • Early adulthood is considered to be the prime of life, physically; however, visible aging does begin in this period. • Health risks in early adulthood include death or injury due to violence and car accidents; males are at higher risk here than females. Other major health problems include HIV and tuberculosis. • In middle adulthood, there is an increasingly perceptible decline in physical attributes and functioning. Women reach menopause and males experience a decline in sexual responsiveness. • Exposure to long hours of strenuous work and lack of access to adequate health facilities hasten the aging process. • Regular exercise and a good diet can slow the aging process and reduce health risks.

• Health risks include increased risk of cardiovascular disease, various forms of cancer, arthritis and respiratory disease. • Lifestyle stress can contribute to mental and physical ill health. • The age range of late adulthood is changing as the global population lives longer. • In late adulthood (senescence), there is an increasing decline of all the body’s systems, and in sensory and psychomotor abilities. • The increasing number of older people is a challenge for the economically active section of the population to support. • South Africans have a lower than average life expectancy and healthy life expectancy. • The experience of health in old age may vary widely, depending on socio-economic status, gender and where people live. • Health risks in late adulthood include greater vulnerability to injuries and infections, and an increase in non-communicable diseases like cancer, diabetes, strokes and hypertension. These are made worse by a lifetime of poor diet, arduous physical labour, multiple pregnancies and inadequate reproductive health care....