Researchers are often struck by gorillas’ apparent humanity. Taking into account our genetic similarities of 95% or above, there has been a long debate about how close humans and gorillas really are. The following summary is from the award-winning Gorilla Highlands Interactive eBook:
The mind of the gorilla has its own mysterious paths that even the most persistent observer may find difficult to trace …
Yet the apes are not under the total grip of their instincts. Learning and tradition play an important role in their lives, a role that is difficult to assess in the wild, because each youngster gradually and unobtrusively learns the things that help it fit into its group and environment. Knowledge of food plants, route of travel, the proper way to respond to vocalisations and gestures—these, and many other aspects, are undoubtedly part of the gorilla’s tradition, handed down as a result of individual experience from generation to generation and constituting a rudimentary form of culture, wrote George Schaller in the 1960s.
Nevertheless he believed that the ape’s brain had evolved to, or just over the threshold of insightful behaviour. He argued that there was no selective pressure for them to evolve more sophisticated brain power and concluded that it was an evolutionary dead-end.
In more recent times there is less certainty and there are major question marks over the validity of the above opinion. It is now questioned whether there is always a relationship between selective pressure and evolution, i.e. is intelligence an evolutionary progression or a freak aberration?
Scientific opinions of the 1960s have been constantly revised to reflect the changing dynamics of gorilla troop formation over time. There is no set troop composition; each develops its own hierarchy and pattern of relationships that develop over time. There is greater variety and subtlety in gorilla behaviour and cognitive processes than was first thought.
According to some researchers gorillas, like other great apes, have individuality, can laugh, grieve, have ‘rich emotional lives’, develop strong family bonds, and can make and use tools. They can have individual colour preferences. In general, gorillas are believed to have ‘cultures’ in different areas revolving around different methods of food gathering.
They can think about the past and future; they use past experiences as a guide for decision-making, which often have a future element. However, it may not be possible for a silverback to communicate a potential benefit to others in the troop, for example fresh fruit or safety.