I got the following info from a couple of sites.
Bonobos and chimpanzees diverged from each other around 2 million years ago and differ in morphology, behavior, and perhaps even emotions and cognition in important ways.
The Bonobo
Bonobos are female dominant, with females forming tight bonds against males through same-sex socio-sexual contact that is thought to limit aggression. In the wild, they have not been seen to cooperatively hunt, use tools, or exhibit lethal aggression.
The Chimpanzee
Chimpanzees are male dominant, with intense aggression between different groups that can be lethal. Chimpanzees use tools, cooperatively hunt monkeys, and will even eat the infants of other chimpanzee groups.
Bonobos and Chimpanzees share close to 99% of their genome in common with humans, meaning that their genomes are more similar to that of humans than they are to that of gorillas. However, it may be that Bonobos, whose psychology is virtually unstudied relative to that of chimpanzees, are more similar to humans than are chimpanzees in how they solve various social problems Such similarities may even be partly the result of shared and heritable neurophysiology that potentially regulates the social emotions of humans and Bonobos in similar ways.
Physical differences:
Despite their colloquial name of “pygmy” chimpanzee, bonobos are actually roughly the same size as common chimpanzees, being only slightly shorter and thinner, with smaller heads. Common chimpanzees have shorter limbs than the more gracile bonobo, and a more prominent brow ridge. Bonobos apparently walk upright more often than chimps, and when walking quadrupedally employ a method of knuckle walking more similar to that of the orangutan than the chimpanzee.
Bonobos:
Chimp:
