WILD chimpanzees display some human behaviour by adopting orphaned infants to give them a better chance of survival, researchers have discovered.

The study by psychologists at St Andrews University found the adoptive 'parents', who can be young brothers or sisters, carried the young infants, waited for them while travelling, shared food with them, and even stuck up for them during fights. Dr Catherine Hobaiter and Professor Klaus Zuberbuhler combined their own observations of adoptions in the Sonso chimpanzee community in Uganda with long-term published records from chimpanzee sites across Africa to reveal for the first time that being adopted significantly benefits orphaned chimpanzees' chances of survival.

They also discovered forming social bonds are crucial for adoption in Africa. They found when mother dies maternal siblings adopt brothers and sisters.