ABSTRACT
THAT mental traits, whether of intelligence, temperament, or character, have an innate basis is a view which is now very generally accepted. The mind does not start as a tabula rasa, but is endowed at birth with potentialities, which no doubt require a suitable environment for their expression or actualization, but which nevertheless set a limit to the attainments of the individual, in the sense that there are certain points beyond which he cannot go no matter how favourable the environment, and in the further sense that the potentialities act selectively upon the environment so that in similar environments some individuals will respond to certain stimuli, while others will remain indifferent to them. So much may be safely said. Not uncommonly, however, we meet with statements both in popular and scientific writings which go a good deal beyond this. Thus, for example, we may be told that mental differences between individuals are due only in a minor degree to differences in the environment, whether physical or social, and are determined for the greater part by inherited factors, or that physical and mental characters are inherited with the same imoisity and obey the same laws of transmission. Is there any warrant for such statements? What do we really know about the laws of the inheritance of mental characters?
