Own Study

Intelligence quotient

The SRB tests, described by Dureman & Sälde (1959), were used for determining the intelligence quotient. One man refused to take the test, and one man and one woman spoke too poor Swedish to be able to do so. One man and one woman did not take the test for various reasons while they were in the hospital, and they lived too far away afterwards for them to be able to take it under standard conditions. With the possible exception of the man who refused, these exclusions could hardly have distorted the results as a whole. One of the men excluded had had his IQ measured while he was doing his military service, but with a different method, and he is not taken up in the following tabulation.

The men had a mean IQ of 98.0 (SD 12.3) and the women one of 100.0 (SID 9.9). Together, they had a mean IQ of 98.6 with a standard deviation of 13.6. The sex difference was not statistically significant.

Three of the men had an IQ under 75. One of them had attended a special class at school (case 29) and many members of his family were mentally retarded. Another (case 25) had a brain injury when he was young, and got epilepsy afterwards; he showed clear signs of brain injury when I interviewed him. The third man (case 26) was a foreigner, and linguistic difficulties may have been the reason for his low IQ; thus, his answers on the synonym test in the battery were below average for his age. The man for whom I had only the IQ from the military service record had got an average score for his age.

These results indicate that transsexuals do not differ from the general population in IQ distribution or mean.