Nadezhda Ladygina was born in the vicinity of Penza. Her father taught music and was the first in the family to receive an education, while her grandfather was a prosperous peasant who bought his freedom from serfdom before the reform. Nadezhda graduated from the first women's gymnasium with a gold medal and in 1908 went to Moscow to enroll in the Moscow Higher Women's Courses. These courses, sometimes mistakenly referred to as "Bestuzhev's," were located in a specially built building on Malaya Tsaritsynskaya Street.

Initially, Nadezhda aspired to study psychiatry but could not score the required points. However, inspired by V.M. Bekhterev's book "Psychology and Life," she decided to dedicate herself to studying animal behavior in comparison with humans and enrolled in the natural sciences department of the physics and mathematics faculty. The teaching at the courses was of a high standard, especially after professors who had left Moscow University joined in 1911.

Nadezhda Nikolaevna was an extraordinarily beautiful woman with luxurious hair and exquisite taste in clothing. Her jewelry and style evoked admiration even in photographs. Her beauty was ethereal, and she was compared to the Beautiful Ladies of the Silver Age. Even the poet Vladimir Mayakovsky dedicated poems to her after meeting at the zoo, where she conducted her observations.

Many portraits of Nadezhda Nikolaevna have been preserved thanks to her husband Alexander Fyodorovich Kots, who invited the best photographers and artists to capture her image. Alexander Fyodorovich taught evolutionary theory and immediately understood that Nadezhda was his one and only. They married in 1911 and lived together for half a century.

Their bond was not only emotional but also based on shared interests. Alexander Fyodorovich had been passionate about zoology and museum work since childhood. He collected a collection of taxidermied animals that became the foundation of the Darwin Museum, officially opened in 1907. Nadezhda Nikolaevna was a co-founder of the museum, alongside animal artist Vasily Vatagin and taxidermist Philip Fedulov. As a wedding gift, they exchanged taxidermied specimens of a lion cub and a white hawk. In 1913, the couple traveled across Europe, studying natural science museums and acquiring exhibits for their collection.

After the revolution, they continued their work on the museum despite the dissatisfaction of officials who did not support their active endeavors. They demanded the construction of a new building for the museum but never received it. In 1962, Nadezhda Nikolaevna and Alexander Fyodorovich were dismissed, which undermined Nadezhda's health. She passed away in 1963, and Alexander survived her for a short time.

The book "The Child of the Chimpanzee and the Child of Man" was partially translated into English and received recognition abroad. Ladygina-Kots's works were highly regarded by scientists, including Robert Yerkes, the founder of the American primatological school, who wrote about her research with admiration.