Given a few seconds or minutes, they could plot a safe retreat. At the same time, if they focused on what was nearest at hand, they could identify all kinds of important details in their environment—footprints and signs of passing predators, or the colors and shapes of rocks that they could pick up and perhaps use as tools.

In the treetops, this powerful vision was built for speed—seeing and reacting quickly. On the open grassland, it was the opposite. Safety and finding food relied upon slow, patient observation of the environment, on the ability to pick out details and focus on what they might mean. Our ancestors’ survival depended on the intensity of their attention. The longer and harder they looked, the more they could distinguish between an opportunity and a danger. If they simply scanned the horizon quickly they could see a lot more, but this would overload the mind with information—too many details for such sharp vision. The human visual system is not built for scanning, as a cow’s is, but for depth of focus.

Animals are locked in a perpetual present. They can learn from recent events, but they are easily distracted by what is in front of their eyes. Slowly, over a great period of time, our ancestors overcame this basic animal weakness. By looking long enough at any object and refusing to be distracted—even for a few seconds—they could momentarily detach themselves from their immediate surroundings. In this way they could notice patterns, make generalizations, and think ahead. They had the mental distance to think and reflect, even on the smallest scale.

These early humans evolved the ability to detach and think as their primary advantage in the struggle to avoid predators and find food. It connected them to a reality other animals could not access. Thinking on this level was the single greatest turning point in all of evolution—the emergence of the conscious, reasoning mind.

The second biological advantage is subtler, but equally powerful in its implications. All primates are essentially social creatures, but because of their intense vulnerability in open areas, our earliest ancestors had a much greater need for group cohesion. They depended on the group for vigilant observation of predators and the gathering of food. In general, these early hominids had many more social interactions than other primates. Over the course of hundreds of thousands of years, this social intelligence became increasingly sophisticated, allowing these ancestors to cooperate with one another on a high level. And as with our understanding of the natural environment, this intelligence depended on deep attention and focus. Misreading the social signs in a tight-knit group could prove highly dangerous.

Through the elaboration of these two traits—the visual and the social—our primitive ancestors were able to invent and develop the complex skill of hunting some two to three million years ago. Slowly, they became more creative, refining this complex skill into an art. They became seasonal hunters and spread throughout the Euro-Asian landmass, managing to adapt themselves to all kinds of climates. And in the process of this rapid evolution, their brains grew to virtually modern human size, some 200,000 years ago.

In the 1990s a group of Italian neuroscientists discovered something that could help explain this increasing hunting prowess of our primitive ancestors, and in turn something about mastery as it exists today. In studying the brains of monkeys, they found that particular motor-command neurons will not only fire when they execute a very specific action—such as pulling a lever to get a peanut or taking hold of a banana—but that these neurons will also fire when monkeys observe another performing the same actions. These were soon dubbed mirror neurons. This neuronal firing meant that these primates would experience a similar sensation in both doing and observing the same deed, allowing them to put themselves in the place of another and perceive its movements as if they were doing them. It would account for the ability of many primates to imitate others, and for the pronounced abilities of chimpanzees to anticipate the plans and actions of a rival. Such neurons, it is speculated, evolved because of the social nature of primate life.

Recent experiments have demonstrated the existence of such neurons in humans, but on a much higher level of sophistication. A monkey or primate can see an action from the point of view of the performer and imagine its intentions, but we can take this further.