Presentation on theme: "The Relationship between Fecundity & Culture. Proximate Determinants Fecundity: denotes the ability to reproduce. Once a girl reaches menarche, she is."— Presentation transcript:
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.