Biased sample

• • The sample was biased in a number of ways​
• • It was from a working-class population à the findings may apply to that social group and not others​
• • The sample was from the 1960s à parental care of children has changed considerably since that time. For example, more women go out to work, so many children are cared for outside the home, or by fathers who stay at home and become the main carer​
• • Research shows that the number of dads who choose to stay at home and care for their children has quadrupled over the past 25 years (Cohn et al., 2014)​
• • If Schaffer & Emerson’s study was conducted today, the findings might be different, meaning the research lacks temporal validity