The Puzzle of Personality

We don’t just “decide” how to feel about the situations we find ourselves in - our feelings and emotional responses just seem to be there. What is it that shapes our different personalities and behavior patterns?

The scientific view is that the mind is a product of the brain, which gives the illusion of an inner “self”. The brain is organized in part by our genes, which of course were shaped by natural selection. We know that genes account for about 50% of the variation in personality and intelligence (identical twins separated at birth are highly similar; identical twins raised together are more similar than fraternal twins raised together; biological siblings are far more similar than adoptive siblings).

Most people conclude from this that the other 50% must come from the environment. There is actually no evidence for this – it is an assumption that if it’s not hereditary, it must be environmental (50% nature, 50% nurture – good compromise).

However the other discovery, which is just as important, though less well appreciated, is that the twins separated at birth are no more different than the twins who are brought up together. If there was an environmental effect you would expect more similarity in twins raised together. Not so. This is considered by some to be the most important puzzle in the history of psychology. The suggestion is that it is not environmental influences which determine the other 50%!

Steven Pinker in “The Blank Slate” concludes that there are chance events in the wiring of the brain both before and after birth, which could determine the remaining 50% of the variation in personality and intelligence. Sadly such views are so weighted down with political, moral and emotional implications that we hardly dare speak of them. Why can we not embrace this amazing knowledge, and accept that we probably cannot shape our children’s personality and intelligence?

The case for respecting the earth

Of course we should respect the earth – it has given us life, it is a beautiful place. Also, we must not forget that our species is a natural product of our earth, and so to a certain extent whatever we do to it is natural. Of course we would like the earth to remain hospitable and beautiful for our children, so we must endeavour to keep it so.

We are already developing the technologies to generate clean and sustainable energy, so that we no longer have to dig out fossil fuels from the earth, blighting the landscape and polluting the atmosphere. Solar, wind, and nuclear fusion power can and will be the future.

We must also respect the fact that the earth can only sustain a finite number of people, and we are fast approaching the time when we will exceed its carrying capacity. Unless we address this issue soon with a workable and global program of birth control, the consequences will be severe for humanity. Overcrowding leads to unhappiness, violence, war, hunger, starvation, disease, and death.

Ultimately, all species become extinct and humans will be no exception. Conditions on the earth at the moment are favourable for the life which exists here. This will change in the future, as the earth is a restless planet – driven by plate tectonics and its changing position with respect to the sun. There is little we can do about this, and it is one of the reasons that there is life here on earth. We should not be so arrogant as to presume that we can control the earth’s climate and its future – nature’s forces are far greater than our own. It is not humanity which is causing the extremes of weather and the natural disasters with which we are so familiar, these events are way beyond our control. We should respect those amazing forces, and appreciate what the earth has given us in our finite time here, as individuals and as a species.