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Stories by Eckhard H. Hess

The Role of Pupil Size in Communication

Changes in attitude can be detected by measuring changes in pupil size. It now appears that enlarged or constricted pupils can also affect the attitude and responses of the person who observes them...

November 1, 1975 — Eckhard H. Hess

Imprinting in a Natural Laboratory

A synthesis of laboratory and field techniques has led to some interesting discoveries about "imprinting," the process by which newly hatched birds rapidly form a permanent bond to the parent...

August 1, 1972 — Eckhard H. Hess

Attitude and Pupil Size

Dilation and constriction of the pupils reflect not only changes in light intensity but also ongoing mental activity. The response is a measure of interest, emotion, thought processes and attitudes...

April 1, 1965 — Eckhard H. Hess

Shadows and Depth Perception

The ability to see that a surface curves toward or away from us depends upon how light and shadow are distributed. Investigators have undertaken to determine if the ability is innate or learned...

March 1, 1961 — Eckhard H. Hess

"Imprinting" in Animals

When ducklings are hatched, the first moving object they see is usually their mother. They proceed to follow her. If they see another moving object, however, they follow it instead

March 1, 1958 — Eckhard H. Hess

Space Perception in the Chick

In which the sight of newborn chicks is manipulated with tiny hoods to determine whether the ability of the birds to locate objects is learned, innate or due to the process of maturation...

July 1, 1956 — Eckhard H. Hess
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