Babies go on cuteness overload in order to be better looked after, scientists say.
Big eyes, chubby cheeks and bubbling laughter are all part of the "act" to trigger care-giving and survival, according to Oxford University researchers.
Similar traits in cuddly and cute animals evoke the same kind of response.
The review is one of the latest studies on how cuteness affects the brain - and the role it plays in care-giving.
Evidence suggests cuteness consists of more than just visual features and also includes smells and sounds.
And cuteness affects both men and women, including those without children, said the researchers writing in the journal Trends in Cognitive Sciences.
Professor Morten Kringelbach of Oxford University's Department of Psychiatry said: "Infants attract us through all our senses, which helps make cuteness one of the most basic and powerful forces shaping our behaviour.
"This is the first evidence of its kind to show that cuteness helps infants to survive by eliciting care-giving, which cannot be reduced to simple, instinctual behaviours.
"Instead, care-giving involves a complex choreography of slow, careful, deliberate, and long-lasting prosocial behaviours, which ignite fundamental brain pleasure systems that are also engaged when eating food or listening to music, and always involve pleasant experiences.
"This might be a fundamental response present in everyone, regardless of parental status or gender, and we are currently conducting the first long-term study of what happens to brain responses when we become parents."