A large proportion of parents consistently favor one child over another. This favoritism can manifest in different ways: more time spent with one child, more affection given, more privileges, less discipline, or less abuse.
Research by sociologist Jill Suitor examines some of the causes and consequences of parental favoritism, which occurs in one- to two-thirds of American families.
Despite its taboo in our society, we consider some cases of parental favoritism to be fair — and even necessary. For example, parents give more attention to newborns than they do to their older children. The same goes for children who are sick or disabled. In these situations, parents often discuss the unequal treatment with the disfavored children in order to assure them that it's nothing personal.
Other reasons for parental favoritism most of us would judge as unfair, yet they don't surprise us much. Parents might spend more time with and feel closer to same-gender children than to opposite-gender children. In mixed families, parents favor their biological children over step-children. In patriarchal cultures, parents simply favor boys over girls.
There are several additional factors that predict favoritism, one of which is birth order: Parents favor first- and last-born children over middle children. This occurs in part because middle children will never be the only child living at home — at some point first-borns and last-borns will have their parents all to themselves. Overall, first-borns get the most privileges and last-borns receive the most parental affection.
A child's personality and behavior can also affect how parents treat them. Parents behave more affectionately toward children who are pleasant and affectionate, and they direct more discipline toward children who act out or engage in deviant behavior. Because girls tend to be warmer and less aggressive than boys, parents generally favor daughters over sons (but only in non-patriarchal cultures).
Favoritism is also more likely when parents are under a great deal of stress (e.g., marital problems, financial worries). In these cases, parents may be unable to inhibit their true feelings or monitor how fair they're behaving. Evolutionary theorists argue that when emotional or material resources are limited, parents will favor children who have the most potential to thrive and reproduce.
Unfortunately, the consequences of parental favoritism are what you might expect — they're mostly bad. Disfavored children experience worse outcomes across the board: more depression, greater aggressiveness, lower self-esteem, and poorer academic performance. These repercussions are far more extreme than any benefits the favored children get out of it (negative things just have a stronger impact on people than positive things). And it's not all rosy for the favored children either — their siblings often come to resent them, poisoning those relationships.
Many of these consequences persist long after children have grown up and moved out of the house. People don't soon forget that they were disfavored by their parents, and many people report that being disfavored as a child continues to affect their self-esteem and their relationships in adulthood.
To make matters worse, parents are even more likely to play favorites once their children are grown up, sustaining the toxic family dynamics (e.g., bad feelings, sibling resentment). The causes of the favoritism, however, are a bit different once the children become adults. Parents still favor daughters and less deviant children, but they also give preference to children who live closer, share the parents' values, and, not surprisingly, have provided the parents with emotional or financial support.
It's important to keep in mind that parental favoritism is only problematic when there are consistent and arbitrary differences in treatment. In cases where favoritism is unavoidable (e.g., with newborns, needier children), parents who explain its necessity to the other children can usually offset any negative consequences.
Interestingly, children's well-being is highest when parents exhibit no favoritism toward anyone, even higher than the well-being of children who are favored by their parents. This disparity may occur because favored children have to contend with sibling hostility, or perhaps because families that practice favoritism tend to be dysfunctional in other ways.
Nearly all parents worry about whether they play favorites. But even when parents vow to treat their children equally, they soon find that this is just not possible. Every child is different and parents must respond to their unique characteristics appropriately. You shouldn't react to a 3-year-old's tantrums in the same way as you would to a 13-year-old's. You can't deal with aggressive children in the same way as passive children. Even identical twins can't be treated identically. When it comes down to it, every child wants to feel like they're different, not clones of their siblings. The best parents can do is stay aware of any differential treatment they give and try to be as fair as possible.
(This post was co-authored by Josh Foster.)