Still from Ode to My Father, 2014, Director: JK Youn

"Developmental psychology has long recognised the social element in thinking. Almost a hundred years ago the Soviet psychologist Lev Vygotsky observed that the emergence of individual thought can be understood as the internalisation of interpersonal dialogue. Young children playing alone often talk to themselves, echoing what sound like the instructions of adults. These clearly resemble the kind of verbal structure they have been given by caregivers. Learning to think for yourself is a process of representing the contributions of others.

"The people around us can also cognitively impair us. A conversational partner who seems to want to avoid a topic can make it surprisingly difficult for you to think about it properly.

"So while my brain is important, cognition exists beyond my head. I make important decisions by consulting with those close to me. I use reminders and rely on family and colleagues to deliberate about plans. This sort of social process is not only supportive of my cognition – it is my cognition. By extension, the extent to which a person is cognitively impaired is a function of the social supports they have around them. That’s not to say that we can wish away the ill effects of brain injury and dementia. Damage to the brain will tend to lead to difficulties in thinking. But to talk about cognitive impairment is to talk about something that couldn’t exist in the same way without the other people who populate our lives." - Huw Green

ARTICLE: The Big Idea: Why Your Brain Needs Other People