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The Relationship between Fecundity & Culture. Proximate Determinants. Fecundity : denotes the ability to reproduce. Once a girl reaches menarche, she is fecund. Demographers John Bongaart & Robert G. Potter study proximate determinants of fertility
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Proximate Determinants Fecundity: denotes the ability to reproduce. Once a girl reaches menarche, she is fecund. • Demographers John Bongaart & Robert G. Potter study proximate determinants of fertility Proximate Determinants are the biological and behavioural factors through which social, economic, and environmental factors affect fertility • Correlation exists between proximate determinants & fertility • Ex. A change in contraceptive use will cause a change in fertility ( either increase or decrease)
Bongaarts & Potter looked at the cultural norms surrounding contraception & birth in both developed & developing countries, as well as those of the “Hutterites” (a religious group similar to Mennonites & Amish)
They discovered that in contemporary Western societies women bear an average of 2 children during their reproductive years (1.5 in Canada) • Marriage generally occurs when a couple are in their early twenties, and their first child follows two years later. The second child is spaced to occur approx. 2-3 years after the first • Contraception is used to delay the 2nd conception, and surgery is used to avoid further births
In the developing world (Africa, Asia, Latin America) women ten to have an average 7 children. • Marriage usually takes place in her teens, & the first child arrives about 3 years after. • Births are generally spaced about 3 years apart & continue until the women enters menopause. • The longer interval is the result of more prolonged and frequent breast-feeding than in Western populations.
The Hutterites have the highest fertility of the various groups studied • They live in small self-contained communities with strict social and religious controls over most aspects of daily life • Women in the culture bear approx. 9 children - with a strict ban on contraceptive use & a shorter period of breast-feeding results in a birth interval of approx. 2 years.
According to cultural norms in many developed counties like Canada, individuals are expected to be independent & autonomous • This expectation is evident as early as infancy - babies are expected to sleep in their own cribs, often left to ‘cry-it-out’, and typically is breast-fed for a short period of time. • According to Health Canada, about 70% of women initiate bread-feeding but up to 40% of them stop nursing by the time infants are 3 months old.
In general, breast-feeding rates are higher among older mothers and those with higher education and income levels. • One of the most common reason citied by Canadian women for quitting breast-feeding was that they had to return to work.
How does breast-feeding affect fecundity? • If done properly or “on demand”, breast-feeding can actually have a contraceptive effects • Specifically, it results in the release of prolactin - a pituitary hormone that regulates the production of another chemical called progesterone which in turn inhibits ovulation • In many developing countries where breast-feeding is done on demand and complete weaning (removal of breast milk from the diet) is carried out between 2.5-4 years of age, births are typically spaced 4-5 years apart
In contrast, countries like Canada who have low breast-feeding rates, births often occur in quick succession
Menarche & Fecundity • Menarche: The age at which a woman experiences her first menstrual period. • Age of menarche is influenced by culture rather than biological occurrence • In pre-industrial nations women • had much less protein in their diets and tended to eat more low-calorie proteins. • Diets made up of wild plant (roots, seeds, leaves, nuts) and game or fish & didn’t include dairy products or processed grains • They travel 10 km or more on foot every day & routinely carry heavy loads, often 15-20 kg • This lifestyle resulted in menarche occurring between 16-18 years of age
First child was born between 3-4 years after. • Since women in these societies tend to breast-feed on demand, ensuing children are born every 4-5 years • This cycle repeated itself 4-6 times until the women reached menopause @ 45, experiencing about 150 ovulations in her life time
Women in developed nations • Eat a diet high in fat, protein, and calories • Experience little physical activity • This has lowered the age of menarche to 12 or 13 & has delayed menopause until 50-55 • Birth of first child delayed 13-14 years AFTER menarche with only 2-3 births which occur in quick succession • The average women will ovulate have over 450 times in her lifetime.
Age of Marriage • Since most people do not begin families until after marriage - the age at which couples marry can have an important impact on the number of children they have.