Conscience grows on temperamental grounds.

Pundits and policy makers frequently call on parents to instill morality in their children, often implying that this trait can be learned by rote, like the multiplication tables. A long-term study of preschoolers now indicates that, to the contrary, the moral beacon known as a conscience develops in different ways, with critical contributions from both a child's natural approach to the world and specific parental practices.

A good fit between a youngster's temperament and a mother's child-rearing style fosters the ability to tell right from wrong and to act accordingly, at least from ages 2 to 5 1/2, argues psychologist Grazyna Kochanska of the University of Iowa in Iowa City.

In fearful children, who display considerable caution, shyness, and anxiety, conscience establishes a beachhead if they receive gentle discipline that puts encouragement over threats, Kochanska says. The overall quality of their relationship with their mother does not appear to play a role.

In fearless kids, who exhibit an outgoing, curious approach to the world, conscience takes root in the presence of a cooperative, emotionally secure relationship with their mother. The child will then heed the mother's direct suggestions for improving behavior, Kochanska explains. When these children do not have a close relationship with their mother, they show less conscience.

"As they move through the preschool period, [fearful children] may internalize rules and norms more rapidly than fearless children," the Iowa scientist remarks. "If replicated in another sample, this [research] approach may help to elucidate some of the central questions of socialization."

Kochanska's study, published in the March Developmental Psychology, consists of 43 girls and 47 boys observed at ages 2 1/2, 4, and 5, give or take several months. Children and their mothers were mostly white and came from families with a wide range of incomes.

At the youngest age, temperament was assessed through mothers' reports and the child's responses to an experimenter's suggestions to play with various lab toys.

Maternal responsiveness and disciplinary style, as well as the child's sense of security and dependence on her, were also rated after observations of their interactions in laboratory sessions.

At the two older ages, Kochanska assessed each child's conscience level in part on his or her ability to resist temptations to cheat during several laboratory games. For instance, children had 3 minutes by themselves to guess which three animals were hidden under pieces of cloth by touching them with one finger, without peeking. An experimenter first explained to each child what cheating means and stressed the importance of not cheating.

Conscience ratings also rested on kids' solutions to hypothetical moral dilemmas, such as whether to ignore a bully or to aid his victim. Fearful children may spontaneously feel anxious at even the thought of wrongdoing, making them relatively quick to develop a conscience, Kochanska suggests.

Fearless youngsters ignore gentle discipline but develop a strong conscience if they have a close relationship with a responsive mother, a tendency the Iowa researcher plans to examine more closely in future research.

Peer and teacher influences on conscience undoubtedly start to grow in strength at about age 5, she notes.

"This study is a nice demonstration of an interaction between childhood temperament and socialization," says psychologist Avshalom Caspi of the Institute of Psychiatry in London.

In the same journal, Caspi and his coworkers report that extremely inhibited or impulsive 3-year-olds encounter many more interpersonal problems as young adults than do somewhat reserved or moderately outgoing 3-year-olds, perhaps indicating that personality development diverges among both fearful and fearless kids depending on how well they mesh with a variety of social influences.