After Dr. Jane Goodall’s early observations of chimpanzees using tools, her mentor, renowned paleoanthropologist and archaeologist Dr. Louis Leakey, famously responded: “Now we must redefine tool, redefine man, or accept chimpanzees as human.”

Although tool use was the discovery that inspired this statement, Dr. Goodall’s decades of research revealed many other similarities between chimpanzees and humans. Her work challenged the idea that humans are completely separate from the rest of the animal world and showed that chimpanzees share many behaviors and characteristics once believed to belong only to people.

Chimpanzees and the Discovery of Tool Use

For centuries, the ability to create and use tools was considered one of the defining differences between humans and other animals. Scientists believed that humans were unique because they could make and use tools intentionally.

That belief changed when Dr. Jane Goodall observed a chimpanzee in Gombe, Tanzania, removing leaves from a plant stem and inserting the prepared stick into an ant nest. The chimpanzee, later named David Greybeard, had created a tool to collect ants.

Dr. Goodall’s discovery demonstrated that wild chimpanzees were capable of using tools, a behavior previously thought to exist only among humans.

Her continued research revealed even more examples of chimpanzee intelligence. Chimpanzees were observed using branches to access insect nests, stones to break open hard fruits and nuts, and even creating sponge-like tools by chewing leaves into absorbent bundles that could soak up water.

Later studies found that different chimpanzee communities have their own unique tool traditions, showing that these behaviors can be learned and passed between generations.

Chimpanzees Are Not Only Plant Eaters

Before Dr. Goodall’s research, many scientists believed chimpanzees mainly ate plants and only occasionally consumed insects.

Her observations revealed a more complex picture. She discovered that chimpanzees also eat meat and actively hunt rather than simply scavenging from already dead animals.

She first witnessed chimpanzees feeding on a bushpig and later documented groups hunting red colobus monkeys. Additional research showed that when chimpanzees eat young monkeys, they often begin with the brain, which may provide valuable fats and fatty acids.

Although hunting is an important behavior, meat makes up only a small portion of their overall diet, accounting for less than 3 percent. Most of their food still comes from plant sources.

Chimpanzees Are Capable of Conflict and Warfare

Dr. Goodall initially described chimpanzees as being similar to humans but perhaps more peaceful. However, her long-term observations also revealed a darker side of chimpanzee behavior.

During her research at Gombe Stream National Park, she witnessed a violent conflict among chimpanzees that became known as the “Gombe Chimpanzee War,” which occurred from 1974 to 1978.

A previously united chimpanzee community divided into two groups. One smaller group, consisting of six adult males, three adult females, and their offspring, separated from the larger group. Over several years, the two groups engaged in repeated attacks, eventually resulting in the deaths of males from the original community.

This discovery challenged the belief that organized warfare was unique to humans. Later studies suggested that the conflict was likely connected to competition for power, territory, and access to resources—motivations also seen in human societies.

Strong Family Bonds Between Mothers and Offspring

While chimpanzees can display aggression, Dr. Goodall also revealed their remarkable capacity for affection, care, and emotional connection.

Young chimpanzees depend heavily on their mothers during the early years of life, much like human children. They are usually not weaned until they are around five years old and often remain close to their mothers for several additional years. Some even maintain lifelong relationships.

During her years at Gombe, Dr. Goodall observed many different parenting approaches. Some mothers were highly affectionate and playful, while others were less involved.

Her research showed that maternal care has a lasting impact on chimpanzees’ personalities and social development. More recent studies from Gombe have found that strong maternal relationships may influence whether male chimpanzees later become dominant members of their communities.

Chimpanzees Show Compassion and Adoption Behavior

One of Dr. Goodall’s most important discoveries was that chimpanzees can show remarkable compassion and generosity.

She documented cases where chimpanzees adopted orphaned young individuals, a behavior that had never been recorded before her observations. These acts of care demonstrated forms of empathy and altruism that scientists once believed were limited mainly to humans.

Many researchers have since observed similar examples of cooperation, emotional support, and kindness among chimpanzees in Gombe and other locations.

Understanding the Connection Between Humans and Chimpanzees

Modern genetic research has shown that chimpanzees share approximately 98.6 percent of their DNA with humans, making them our closest living relatives.

However, Dr. Goodall recognized the similarities between humans and chimpanzees long before genetic studies confirmed this connection. Through patient observation, she demonstrated that the boundary separating humans from other animals is not as clear as once believed.

As she famously explained:

“Chimpanzees, more than any other living creature, have helped us to understand that there is no sharp line between humans and the rest of the animal kingdom. It’s a very blurry line, and it’s getting more blurry all the time.”

Jane Goodall’s Continuing Legacy

Dr. Goodall’s groundbreaking discoveries continue through the work of the Jane Goodall Institute. Research at Gombe has become the longest-running study of wild chimpanzees in history, lasting more than 60 years and continuing today.

The area now supports many scientific projects, including studies of rare hybrid monkeys and long-term research on wild baboons.

Beyond her contributions as a scientist, Dr. Goodall became a leading conservationist and founded the Jane Goodall Institute to protect chimpanzees, endangered wildlife, and the forests they depend on.

Her lifelong work reminds people that protecting chimpanzees and preserving the natural world is a responsibility shared by everyone.