Parents who believe their young teen is likely to drink excessively may prompt him or her to adopt drinking behaviors that mirror those negative expectations, according to a study from Iowa State University.

On the other hand, parents with positive expectations had little effect on their child’s drinking pattern.

“Even though self-fulfilling prophecy effects are small, unfavorable beliefs are having cumulative self-fulfilling influences,” Dr. Stephanie Madon told AMN Health.

“Parents who overestimate their child’s risk of alcohol use are, through this self-fulfilling prophecy effect, eliciting a greater degree of alcohol use from their child,” she said.

Madon and others conducted a study involving 115 Iowa seventh-graders and their parents.

At the start of the study, parents were asked about their child’s alcohol use, including whether they believed their child would drink an alcoholic beverage offered by a friend at a party. They were also asked to rate on a scale of 1 to 10 how likely they believed their child was to drink regularly during his or her teen years.

Children were asked about their alcohol use, including the number of times they consumed three or more alcoholic beverages at a time, both at the start of the study and 12 months later.

In general, children’s alcohol use at the end of the study period was influenced both by their past alcohol use and by their perceptions of their friends’ drinking behaviors, Madon and her team report in Psychological Science.

Alcohol use was greatest, however, when mothers and fathers both overestimated their child’s drinking, the report indicates.

The assumption is that a parent who believes his or her child is at risk “behaves in a certain way that causes the child to be a drinker,” Madon said.

When one parent underestimated and the other overestimated their child’s future alcohol use, however, the child exhibited less drinking. The underestimation “tended to buffer children against increased alcohol use,” Madon and her team write.

Overall, the study’s finding suggest that negative self-fulfilling prophecies have cumulative effects for members of stereotyped groups. “People who are often viewed unfavorably by lots of different people are at a particular disadvantage,” Madon said.

Yet, since the findings also show that just one parent’s underestimation seemed to protect the child from fulfilling a negative prophecy, it suggests that “members of stereotyped groups may be shielded from confirming negative stereotypes if they are also exposed to positive beliefs,” the researchers conclude.

SOURCE: Psychological Science, December 2004.