Goodall insists that these gestures are evidence of `` the close , supportive , affectionate bonds that develop between family members and other individuals within a community , which can persist throughout a life span of more than 50 years '' . Goodall insists that these gestures are evidence of `` the close , supportive , affectionate bonds that develop between family members and other individuals within a community , which can persist throughout a life span of more than 50 years . ''