When NBC commemorated the hit 1980s television series “The Cosby Show” with a two-hour special last Sunday, the work of one Harvard Medical School professor got another chance to shine.

Professor of Psychiatry and Associate Dean for Student Affairs at the Medical School Alvin F. Poussaint joined Bill Cosby to develop the show and consulted on almost every episode during the show’s eight-year run, fine-tuning its educational message with his insights into child psychology. He reworked the show’s script to give it the human appeal and positive message that made the show a landmark.

“I had nothing to do with the humor on the show, that was all Cosby,” Poussaint explains.

Rather, the psychiatrist’s role was to “foster a discussion” on the storyline and character development of each episode. Poussaint attended taping in New York almost every week, getting to know the show’s actors and writers.

“We became kind of a big family down there,” he recalls.

Poussaint and Cosby began working together in the late 1970s, when Cosby was taping educational documentaries and needed help evaluating scripts. This collaboration later led to discussions about how to develop what would become “The Cosby Show.”

Cosby, who has a doctorate in education, and Poussaint, who has worked extensively on child development, family health and violence, worked well together.

“We were basically on the same wavelength,” Poussaint says.

The agreed goal was to create a comedy show that would be healthy for all children, especially black children.

Positive images of parenting and lots of father involvement came through in every episode. Claire and Cliff Huxtable, the names of the show’s fictional wife and husband duo, displayed a mutually supportive, loving relationship.

These are factors that made “The Cosby Show” universally popular, Poussaint says. “Cosby was confident that he was touching on issues important in any family—you know, school problems, sibling rivalry, dirty room, goldfish dying.”

The psychiatrist approached each episode as an educational opportunity—children watching the show could learn in half an hour, for instance, how a driving lesson works.

At the same time, Poussaint and Cosby prioritized keeping the show in a “black cultural context,” evident in the African art on the walls and Cosby’s sweatshirts of historically black colleges.

In the conservative industry of network television, showing that a healthy black family and a comedy show are not mutually exclusive categories was a big breakthrough.

“The Cosby Show” wasn’t the first black situation comedy, but earlier shows like “The Jeffersons,” “That’s My Mama” and “Good Times” all depended on some sort of “clownish buffoonery” for laughs, Poussaint says.