.  Are some people born clever and others born stupid? Or is intelligence developed by our environment and our experience? Strangely     11    , the answer to both these questions is yes. To some extent our intelligence is given us at birth, and no amount of special education can make a genius     12    a child born with low intelligence. On the other hand, a child who lives in a boring environment will develop his intelligence less than one who lives in rich and varied surroundings. Thus the     13    of a person's intelligence are fixed at birth, but whether or not he reaches those limits will depend on his     14    . This view, now held by most experts, can be supported in a number of ways.
    It is easy to show that intelligence is to some extent     15    we are born with. The closer the blood relationships between two people, the closer they are likely to be in intelligence. Thus if we take two unrelated people     16    from the population, it is likely that their degrees of intelligence will be completely different. If on the other hand we take two identical twins, they will very likely be as intelligent as each other. Relations like brothers and sisters, parents and children, usually have     17    intelligence, and this clearly suggests that intelligence depends on birth.
        18    now that we take two identical twins and put them in different environments. We might send one, for example, to a university and the other to a factory where the work is boring. We would soon find differences in intelligence developing, and this indicates that environment     19    birth plays a part. This conclusion is also suggested by the     20    that people who live in close contact with each other, but who are not related at all, are likely to have similar degrees of intelligence.11.