Early development

Hi~ in a sentence underlined below, what could be the meaning of "early development"?

Infant period ? OR the beginning stage the bias is formed?

It might not be easy to figure out but when you determine from the context, what do you think about that?

Any idea would be welcomed. Thank you in advance!

THE EARLY FORMULATION OF BIAS
Most of our implicit biases are formed either before we can defend against them or by the patterns in our environment that are unavoidable. Therefore, biases are formed by the little things we experience during our
early development—the stories, comments, and even jokes people tell concerning a group of people. Other biases are a product of the saturation of information that is a product of today’s instant media. Once a story breaks, you cannot avoid it. It is on the television, radio, Internet, and in the newspapers. Once a storyline presents a persistent pattern and is repeated over and over for an extended period of time, it is hard not to develop implicit biases. In addition, a person’s environment often produces implicit biases. The nuances of a person’s job begin to influence
individuals over time. The workplace often produces some of the stronger implicit biases that humans develop.