|Twins are very special as they allow researchers to look at how "nature" (our genetic makeup, or genes) and "nurture" (our
experiences) affect different human characteristics (such as our personalities or how tall we are). Most of our characteristics
are caused by both our genes and our environment, but it is difficult to work out how much a characteristic is caused by
nature and how much of it is caused by nurture. For example, I love cheese, but is this because I was born with a love of
cheese, or because half of my family are French and I grew up surrounded by lots of cheese so acquired a taste for it?!
Studying twins can help us to find out the answers to questions like these. The diagram below shows how both nature and
nurture influence our characteristics.
Identical twins are often so similar to one another that they're described as being like "two peas in a pod". This is because they have exactly the same genes - the building blocks that we get from our parents that make us who we are. Non-identical twins, on the other hand, only have about half of the same genes, and are no more similar to each other than regular brothers and sisters. But both types of twins grow up in the same environment, and are nurtured in the same way by their Mum and Dad. This means that researchers can compare similarities between identical twins, and similarities between nonidentical twins, to get an idea about how much a characteristic such as height is caused by nature (genes), and how much by nurture (experiences).
Recently, some research studies have compared twins in this way to understand how nature and nurture influence our eating characteristics, such as the types of food we like most (or like least, such as brussels sprouts for me!) and how much we enjoy the experience of eating.
Researchers have found that quite a few of our eating characteristics are greatly influenced by our nature (or genes). These include: