Babies are great. They're adorable, only occasionally smell bad, and — best of all — are blissfully ignorant of the world's cruel indifference. If you don't like babies, something is wrong with you.

But let's face it: Babies are manipulative, too. And a new study by psychologist Hiroko Nakayama in Japan seems to reaffirm what many perpetually sleep-deprived moms and dads have long suspected: Babies will fake cry to get what they want.

Researchers carefully analyzed two infants — Baby R and Baby M — through dozens of tearful episodes, and sought to pin down two specific states before and after crying spurts: Positive emotions (smiling/laughing) and negative emotions (frowning or appearing genuinely upset about something). Here's what they found:

In total, 102 crying episodes were analyzed. The infants displayed negative affect almost always just before starting to cry and soon after crying terminated. However, there were exceptions. Positive affect was observed. These were crying behaviors that the mother identified as "fake crying" or "emergence of fake crying." These data indicate that, although normally infant affect just before and right after crying is negative, infants also can exhibit positive affect when they show fake crying. [PubMed]

Most of the time the crying really was because Baby R and Baby M were unhappy: 98 percent of Baby R's crying bouts came after something negative. But one day, at around the 11-month mark, a tearful episode was preceded and followed by laughs and smiles. "Infant R appeared to cry deliberately to get her mother's attention," said Nakayama, "[then] she showed [a] smile immediately after her mother came closer."


That's not to say fake crying is a bad thing. We're all manipulative to an extent. Nakayama asserts that fake crying is a sign of emotional health, and "contributes not only to an infant's social development, but also their emotional development. Infants who are capable of fake crying might communicate successfully with their caregivers in this way on a daily basis."

Adds Nakayama: "Fake crying could add much to their relationships."

Sources: Research Digest, via Digg