Page:Popular Science Monthly Volume 76.djvu/338

334 Habit on the Welfare of the Offspring," together with a research of Heron's on "The Influence of Home Environment and Defective Physique on the Intelligence of School Children." These researches "show clearly the small influence of environment." The author on page 28 writes:

That they are contrary to current belief I do not deny, but to say that they are unexpected shows little grasp of the whole biological question of modification or knowledge of results of earlier workers. In fact it will be very surprising if any one succeeds in demonstrating an important environmental control acting on psychological differences, exhibited in mental and moral traits. All the evidence that we possess renders it highly improbable that any of the ordinary differences in human environment, such as riches or poverty, good or bad home life, have more than a very slight effect in modifying these complex and high organic functions the improvement of which is the hope of the altruist and the reformer. Not only do the collected facts indicate as much, but the reasons for the same are not difficult to understand if we consider the laws of diminishing environmental control.

Each organism, whether high or low in the scale of evolution, has from the time of conception and beginning of cell-division and segmentation onward through embryonic and post-embryonic life an expected environment. In other words, it expects to develop and live under conditions which are essentially similar to those which surrounded its immediate ancestors at each stage of their career.

If the expected environment is altered, then the modification which will accrue will in general diminish, (1) in proportion as the change from the expected is less and less in amount. This will follow as a