It is difficult to determine accurately how many people have affairs because people may be reluctant to admit to an affair, even for research. For example, a study of almost 5,000 married women found that in face-to-face interviews, 1% of the women said that they had been unfaithful to their husbands in the last year, but with the anonymity of a computer questionnaire, 6% of the same group of women answered yes to this question (Whisman & Snyder, 2007). The NHSLS, with its sample of 3,432 Americans ages 18 to 59, found reported rates of extra­marital involvement at some time during marriage of 25% of married men and 15% of married women (Laumann et al., 1994). A more recent study in 2011 found that over 23% of men and 19% of women said that they had "cheated" during their current relationship (Mark et al., 2011). ■ Table 13.2 shows a global comparison of the percentage of adults who say they have had an extramarital affair.