Introduction
Lies can be placed on a continuum ranging from purely self-serving lies, which benefit the liar at others' expense, to altruistic lies, which benefit others at the liar's cost. Adults, adolescents, and preadolescents decide whether to lie or tell the truth by weighing costs and benefits for themselves and the message receiver. In sender-receiver games, they are most likely to lie for mutual benefit. Additionally, unlike adults, adolescents and preadolescents are more likely to lie when lying incurs a personal cost than when it negatively affects another player. Moreover, preadolescents are more self-oriented than older groups: they lie as readily for mutual benefit as for their own benefit.
Purpose
Although prior studies with adults, adolescents, and preadolescents show clear cost-benefit tradeoffs, it remains unclear how cost-benefit ratios influence primary school-age children's decisions to lie or tell the truth.
Method
We examined 52 children aged 6 to 10 using a modified sender-receiver game. In a within-subjects design, we manipulated payoff rates for the child (the sender) and a fictional partner (the receiver).
Results
The material cost-benefit ratio influenced children's decisions to lie or tell the truth, ꭓ²(2, 52) = 9.45, p = .009. Children were more likely to lie for their own benefit (z = 2.75, p = .003) or for mutual benefit (z = -3.33, p < .001) than solely for the other player. However, there was no difference in lying rates when both parties benefited compared to when only the liar benefited (z = -1.31, p = .096).
Conclusion
Our findings confirm that 6- to 10-year-olds engage in a quasi-rational evaluation of cost-benefit ratios when making decisions. Similar to preadolescents, children's choices to lie or be truthful rely more on costs and benefits for themselves than on outcomes for the recipient.