Meta-analysis involves piling up all the quantitative studies ever done on a particular topic to assess quantitatively what is known about the size of the effect. The pioneering work on meta-analysis (M. L. Smith and Glass 1977) addressed the question: Does psychotherapy make a difference? That is, do people who get psychotherapy benefit, compared to people who have the same problems and who don’t get psychotherapy? Since then, there have been thousands of meta-analyses, but most of them are in fields like psychology and medicine, where data from experiments lend themselves to direct comparison.
A few anthropologists, though, have done important meta-analyses. Until the 1970s, conventional wisdom had it that hunters and gatherers lived a precarious existence, searching all the time for food, never knowing where their next meal was coming from.
TIPS FOR SEARCHING ONLINE DATABASES
- 1. Get the spelling right. Some databases have intelligent spell checkers (if you ask for information on ''New Guinae," they'll ask if you really meant ''New Guinea''), but many don't. If you ask for references on ''apropriate technology'' and the database comes back, incongruously, with ''nothing found,'' check the spelling with your word processor's spell check or with an online dictionary.
- 2. If there are two or more ways to spell a word, then search with all spellings. Use both Koran and Qur'an (and several other spelling variants) in your searches; behavior and behaviour; Chanukah and Hanukah (and several other spelling variants); Rom and Roma (both are used to refer to Gypsies); Thessaloniki and Salonika; Mumbai and Bombay; Beijing and Peking; and so on.
- 3. Use wildcards liberally. Search for ''behav* measur*'' rather than ''behavior measurement.'' That way, you'll capture ''behaviour measurement,'' ''behavioral measurement,'' ''behavioral measures,'' and so on. I asked MEDLINE for articles from 1990 until June 2009 on (child* diarrhea) OR (infant* diarrhea) and got 11,541 hits. I used the wildcard asteriskto indicate that I wanted any records with the words ''children's'' or ''childhood'' and any records with the words ''infant's'' or ''infantile.'' Then I remembered that the British spelling of ''diarrhea'' is ''diarrhoea'' so I changed the parameters to (child* diarrh*) OR (infant* diarrh*) and got another 4,061 hits.
- 4. Become really facile with the Boolean operators (AND, OR, NOT) to narrow your searches. Changing the MEDLINE search to [(child* diarrh*) OR (infant* diarrh*) AND (cultural factors)] reduced the number of hits from over 15,000 to 5. I asked MEDLINE for all articles from 1977 to 2009 on (regimen compliance AND malaria). That search brought back abstracts for 81 articles. When I restricted the search to [(regimen compliance AND malaria) NOT Africa], I got back 57 abstracts. The parentheses and brackets in Boolean searches work just like equations in algebra. So, that last search I did fetched all the items that had ''regimen compliance'' and ''malaria'' in their titles or abstract. Then, the items were sorted and any of those items that contained the word ''Africa'' was dropped.
In 1970, Esther Boserup made the important observation that plow agriculture takes more time than does hoe agriculture. And in 1972, Marshall Sahlins generalized this observation, arguing that hunter-gatherer societies had more leisure than anyone else and that people have to work more and more as societies become more complex.
In 1996, Ross Sackett did a meta-analysis of 102 cases of time allocation studies and 207 energy-expenditure studies to test Sahlins’s (1972) primitive-affluence hypothesis. Sackett found that, indeed, adults in foraging and horticultural societies work, on average, about 6.5 hours a day, while people in agricultural and industrial societies work about 8.8 hours a day. The difference, by the way, is statistically very significant (Sackett 1996:231, 547).
Meta-analysis can be delightfully subversive. Morrison and Morrison (1995), for exam?ple, found that only 6.3% of the variance in graduate-level GPA is predicted by performance on the GRE quantitative and verbal exams. And White (1980) found that across a hundred studies up to 1979, socioeconomic status explained, on average, an identical 6.3% of the variance in school achievement. The raw correlation across those hundred studies, ranged from —.14 (yes, minus .14) to .97.
Meta-analyses are becoming more and more common as electronic databases, including databases of ethnography, develop. Meta-analysis gives us the tools to see if we are making progress on important question. It is, as Hunt (1997) says, the way science takes stock.
Anthropology in the military and in intelligence: For contrasting takes on the activities of anthropologists in Thailand during the Vietnam War, see Wolf and Jorgensen (1970) and Hinton (2002). For an exhaustive historical account of the issue, see Wakin (1992). For opposing views of anthropologists’ involvement in the wars in Iraq and Afgahanistan, see Price (2003) and McFate (2005); see also Gonzalez (2007) and Kilcullen (2007). For a summary of this debate, see Fluehr- Lobban (2008).
Ethical issues in anthropology: Anspach and Mizrachi (2006); Borofsky (2005); Cantwell et al. (2000); Caplan (2003); Carrithers (2005); Cassell and Jacobs (1987); Cushman (2004); Edel and Edel (1968); Einarsdottir (2006); Feinberg (2007); Fluehr-Lobban (2002); D. Gordon (1991); E. Harrison (2006); F. V. Harrison (1997); Kemper (1997); MacClancy (2002); Montgomery (2007); Pels (2008); Posey (2004); Rynkiewick and Spradley (1976); Silverman (2004).