- As a result of the ecological conditions of early humans, we have broadened our inner and outer horizons.
- Humans, but hardly other animals, can plan for their future needs.
- We must choose between satisfying our current desires and postponing our gratification to the future.
From an evolutionary point of view, a central question is why we are the only species that has language. Before attempting to answer that question, the ecology of our ancestors must be considered. One explanation for what happened when the ancestors of humans (hominins) separated from those of chimpanzees some six to eight million years ago is that the hominins adapted to life in open landscapes, while the early chimpanzees remained in forests or denser vegetation. The adaptations to a savannah landscape provided new evolutionary pressures on the hominins, who had to travel over larger distances. Foraging demanded planning for longer periods of time. In brief, the ecology forced the hominins to broaden their spatial and temporal horizons. We have become the far-ranging apes.
The selection pressures, however, also affected the inner worlds of the hominins. In the same way, as they needed to see further across the savannah, they needed to be able to see further within themselves. The evolution of human thinking is closely connected to how we have succeeded in broadening our inner and outer horizons. My thesis is that the unique position of humans is due to the fact that we are the only animals that can plan for future needs and not just for the needs we have here and now. Much of the analysis of the minds of animals and humans concerns how rich their images of the future are. Evolution has given humans an increasingly rich inner world.
An imagined future
The main advantage of an inner world is that it makes it possible to go through an imagined future before the real one falls upon you. To the extent that you manage to foresee the consequences of your choices, you are in a better position to control the future. The essence of planning is that, in contrast to trial-and-error, an individual imagines a series of actions that will lead to a desired goal before carrying out the actions. One should however distinguish between immediate planning, which aims at fulfilling current desires, and prospective planning, which aims at satisfying future desires.
It was, for a long time, assumed that humans were the only animals capable of prospective planning. We can foresee that we will be hungry tomorrow and save some of the food; we realise that it will be cold and windy in winter and build ourselves a shelter well in advance. We sow and we harvest. Humans live in their dreams and plans – notions that carry them away, but also give them perseverance. This applies to all kinds of distant goals: to earn a degree, to build a house, to write a book, to be with the one you love, and so on. Imagination is our strongest driving force.
What makes it harder to plan for future needs than for present ones? The answer is that the two types of planning rely on different levels of imagination. When planning to satisfy a current need, the value of the consequences is determined in relation to what one wants to do at the moment, but it does not require conscious thought about the need. Planning for future needs, on the other hand, requires the ability to imagine and value these potential needs even though one is not experiencing them now.
Yet much of what animals do seems to be planning for the future: birds building nests, squirrels gathering food for the winter, among other things. But these behaviours are only instinctive. Most animals seem to have no idea of the future – they just follow their urges.
Other animals are able to plan
The hypothesis that only humans can plan prospectively can, however, no longer be upheld, in the light of recent experimental results. Great apes are able to outcompete current drives in favor of future ones as well as being able to envision future events. An example is that in Furuvik Zoo, in Sweden, the male chimpanzee Santino has been observed calmly collecting stones in a pile in the morning, and later in the day throwing them at visitors that he becomes angry with. Interestingly, this ability to plan for future needs also seems to have evolved independently in the avian taxon of corvids. For example, scrub jays save food that they will prefer for breakfast tomorrow. Even though these results show that some animals have the capacity for prospective planning, the time range and variations of the plans are rather limited in relation to the capacity of humans.
The difference between immediate and prospective planning can be seen, for example, in the use of tools. Apes and other animals make tools, but almost only for their current needs. Humans, on the other hand, may realize that they will need the tool tomorrow as well and thus carry it with them to a new environment. Signs of carrying tools, therefore, become an interesting test of whether you are capable of prospective planning or not. Stone tools dating back some 2.5 million years have been found in the so-called Oldowan culture. Archaeologists have been able to show that many of these tools were transported over several kilometres. In contrast, studies of chimpanzee tool use have mostly seen them carrying their tools a few hundred metres. This suggests that is a marked difference in prospective planning ability between apes and early humans. It is clear, however, that human foresight has become more extensive over time and nowadays we are constantly juggling the future. We carry not only tools but also tickets, almanacs, mobile phones, and other items.
Prospective cognition gives rise to a fundamental predicament. The dilemma is that the actions required to satisfy future needs are often in conflict with those that satisfy present desires. If I don't want to freeze later tonight, I must go out and look for firewood, but right now I am warm and cozy and have no desire to leave the fire. We have to choose between acting for the present or for the future. There are big individual differences in how we deal with the conflict between our present desires and the future needs we can foresee. The differences are well illustrated by Aesop's fable of the ant and the cricket. Some people, like the ant in the fable, find it difficult to live in the present and get their greatest satisfaction from planning for the future. They take out retirement insurance at the age of 25.
A world real and imagined
When humans acquire the ability to choose their own ends and to plan and dream accordingly, they become more flexible beings, but at the same time, their paradisiacal innocence is ended. They become dual natures, living in both a real and an imagined world. The imaginary world can easily become a seductive refuge – a heaven of fantasy – that overshadows the grey, often arduous everyday life. It is tempting not to connect the two worlds, to let the imagination gallop away with no requirement for action in the real world. The inner world becomes a gnawing longing and the inability to realise it leads to constant frustration.
In this way, the rich inner world of humans has become a burden to us – much as the male peacock has to drag around his gaudy tail to attract the females. Perhaps it is better to come to one's senses, abandon the most alluring castles in the sky and strive to anchor one's thoughts in the reality in which one finds oneself, even if it is far less tempting.
Osvath, M. (2009). Spontaneous planning for future stone-throwing by a male chimpanzee. Current biology, 19(5), R190-R191.
Gärdenfors, P. (2006) How Homo Became Sapiens, Oxford University Press.
Gardenfors, P. & Osvath, M. (2005). The evolution of anticipatory cognition as a precursor to symbolic communication. In Proceedings of the Morris Symposium on the Evolution of Language.