Konrad Lorenz was born in 1903 in Vienna. From an early age, Lorenz was fascinated with animals, collecting a menagerie of various animals he'd found and nursing sick animals at the local zoo. While studying medicine, he continued his work observing animals and became particularly interested in their behavior. After finishing his medical degree, Lorenz went on to attain a PhD in zoology in 1933 and quickly got to work publishing some influential papers on animal behavior [source: Hess].
Oskar Heinroth, a fellow scientist and friend of Lorenz, was actually the first to identify and record the phenomenon of (what would later be known as) erroneous imprinting. Heinroth noticed that, unlike certain other species, greylag geese can attach to humans instead of their own mother straight out of the egg. Lorenz would be the one to experiment with the idea and name the phenomenon "imprinting" (he used the German word prägung). Lorenz studied this process in greater depth to discover the exact conditions necessary for birds to attach to humans and the various effects a human parent can have.
In one experiment, Lorenz separated a nest of goose eggs into an experimental group and a control group. He took the experimental group to raise apart from the mother but left the control group with her. The experimental geese only met Lorenz — not their goose mom — when they hatched and attached to him as their mother. To test his hypothesis about the hatchling-mother bond, he marked the two groups and put them together under a box. Sure enough, when he brought in the mother goose and lifted the box, the control group waddled back to their mother, but the experimental group came to him. He named this phenomenon of certain birds learning who their parents are filial imprinting.
Through further experiments, this time with jackdaws, Lorenz attempted to learn about what he called sexual imprinting, an animal's process of figuring out its proper mate. Indeed, he found that when birds sexually imprint on another species, they will try to mate with members of that group. Interestingly, though, a bird sexually imprints on a species and not on an individual. For example, Lorenz found that when a bird sexually imprints on a human, the bird will try to mate with a human — but not the one who raised it. In addition, different types of imprinting occur at different times as birds mature: One of Lorenz's jackdaws learned to eat with humans and fly with crows but mate with its own species [source: Harre].
Lorenz emphasized that imprinting was unlike other forms of learning for two reasons. First, it happened during what he called a critical period — a definite phase during which the learning had to occur (although this varied depending on the species). Second, Lorenz argued that imprinting was permanent and irreversible. Next, we'll explore how further research called into question some of Lorenz's conclusions.