Chimpanzees reassure each other during times of tension and fear. For example, female chimpanzees, defending their offspring during a conflict with another male or female chimpanzee attempting to rise in the dominance hierarchy, employ threats and intimidation to win. Sometimes this behavior leads to a fight but most often chimpanzees relieve the tension through submission and reassurance. Contact is a very important part of the reassuring process that lessens the fearful chimpanzee's tension and excitement.
Jane's observation:
When a chimpanzee is suddenly frightened he frequently reaches to touch or embrace a chimpanzee nearby, rather as a girl watching a horror film may seize her companion's hand. Both chimpanzees and humans seem reassured in stressful situations by physical contact with another individual. Once David Greybeard caught sight of his reflection in a mirror. Terrified, he seized Fifi, then only three years old. Even such contact with a very small chimp appeared to reassure him; gradually he relaxed and the grin of fear left his face. Humans may sometimes feel reassured by holding or stroking a dog or some other pet in moments of emotional crisis.