These days imagination is recognised as playing a central role in human thought, from planning and creativity to memory and problem-solving. It protects our mental health and may even be the fragile foundation on which human society is built. It's thought making up imaginary worlds may be essential in maintaining our health. According to Steven Mithen, an anthropologist at the University of Reading, UK, who specialises in the evolution of the mind, seven key changes were needed to allow the emergence of human imagination as we know it. Each happened for other purposes, the first three in our distant ancestors, but the final four exclusively to Homo sapiens - though we think other animals imagine.
1 Theory of mind
What is it? The knowledge that others have beliefs and thoughts that are different from one's own. Probably evolved in response to larger social groups
How does it support imagination? Allows "thought experiments" about thoughts and behaviours of others
2 Human life history
What is it? A long period of infant helplessness plus an extended childhood and adolescence. May have evolved to resolve the conflict between bipedalism – which narrows the pelvis – and large brain size
How does it support imagination? Enables an extended period with no adult responsibilities, giving the opportunity for imaginative play. Teenage ends at about 25 in physical terms.
3 Specialised intelligence
What is it? The evolution of dedicated mental modules to deal with specific types of thought or behaviour
How does it support imagination? Allows the combination of different types of knowledge or ways of thinking to create new ideas
4 Language
What is it? Strictly speaking, a system of words and grammatical rules. Mithen argues that only Homo sapiens evolved true language
How does it support imagination? Enables the creation, sharing and elaboration of ideas that couldn't have been conceived of in a single human mind
5 Cognitive fluidity
What is it? Using language to more efficiently combine specialist knowledge across cognitive domains
How does it support imagination? Allows the creation of novel thoughts and ideas including metaphors and symbols
6 The extended mind
What is it? The use of technologies such as writing and computer chips to store and share ideas
How does it support imagination? Allows existing ideas to be built on and improved
7 Sedentary lifestyle
What is it? The transition from nomadic hunter-gathering to settled farming lifestyles
How does it support imagination? Through a massive expansion of the shared, extended mind and also the creation of food surpluses so individuals could spend time on creative pursuits
This doesn't really define imagination, but does suggest it is not as much 'in brain' as we have traditionally imagined. Memories used by the imagination are often fractured and not accurate and it can be difficult to separate memory and imagination. This is the beginning of the scientific view of imagination and at some point we start to see links with Molly's mystics and the intuition RP mentions in what we normally term hypothetico-deductive method.