What you accomplish in this world depends upon several things. One is the nature of the abilities with which you are born. A second is whether or not you use these abilities in the most afficient way. A third factor is the conditions under which you use your abilities.
You cannot be told by psychology how to be born with certain abilities. This chapter will be devoted to finding out what surroundings, conditions of light, temperature, ventilation, and health will do most to further your efficiency.
~ Dr. Donald Laird, Increasing Personal Efficiency (1936)