I’ve recently been spending a lot of time with a baby, and one thing I’ve noticed is that much of their behavior is effectively random. Their motions are often erratically motivated, and even when purposeful, are jerky to the point of distraction (e.g. they may lose their balance while sitting and lean forward to discover their feet and change their whole plan). Their utterances seem unprompted, and do not correspond in timing or content to the utterances of those around them or to stimuli except in rare cases.
However, these random actions and utterances provoke very non-random responses in the adults that witness them. This strikes me as expected. Babies are exploring a world they know nothing about. Random input seems like a reasonable heuristic to use to explore a completely unknown thing. Imagine yourself trying to understand a box. You don’t know how to open it, you don’t know what’s inside, you don’t know who made it or how or why. A reasonable approach would be to pick up the box turn it over in any which way, rotate it, look at it from different angles under different lights, weigh it in one hand and then the other, shake it – to exert random stimuli upon it and then to observe how it behaves.
This is what babies are doing to the world and to everything they find in it. They start from a place of much greater ignorance. In the box example, we understand what a box is, what it means to open a box. We have certain expectations and learned understandings about the box even before we examine it. But we exert random stimuli on those parts with which we are unfamiliar. Similarly a baby exerts random stimuli on everything.
Where does this randomness come from? It must be generated in the brain, but it need not be generated by a dedicated brain system. We might compare it to a computer that uses the motion of the mouse to generate random numbers. In the same way, a brain could generate random stimuli by sampling its other systems.
It also seems as though the ability to produce random stimuli could be selected for. In exploring a box or any other puzzle, the ability to creatively explore the puzzle, and the degree to which our exploration is constrained or not by our presuppositions, and the manner in which it is so constrained, can affect how successful we will be at solving the puzzle or understanding the Box. A system that produces good randomness, and does so at the right time and for the right puzzles, could mean an individual solving a problem that leads to e.g. more effective hunting, etc.
This seems particularly true for very young children. The right mix of random actions could mean faster acquisition of the building blocks of understanding, which could have significant long-term cognitive consequences.