Every aspect of our mental lives plays out in two versions: one conscious, the other unconscious. This hidden aspect, of which we are unaware, dictates our relationships, our decisions, our actions.
Over the past twenty years, scientists have discovered new tools to probe our subliminal minds and uncover its secrets, leading to new understanding of the way we experience the world – perception, memory, behavior and social judgment.
New tools like the fMRI, which became widely available in the mid-1990s, according to Dr. Leonard Mlodinow. With the fMRI, you can see what part of the brain is active and functioning at any given time.
"Before that, psychology was a much softer science. It was based on behavioral studies and people would be put in certain situations and observed and questioned. But without the ability to look into the brain and to connect the behavior to a real physical process, it was very hard to really know what was going on. In the last 10, 15, 20 years we've made tremendous progress in understanding the unconscious," he explained.
In his book, Mlodinow pulls back the curtain that hides the darkest corners of our minds. What’s in your unconscious? How can we access its secrets and use them to better understand ourselves?
Mlodinow said he had a realization about the unconscious as he delved into neuroscience. "We also misperceive our inner life or emotional life, our social perception, if we don't understand our unconscious, because it has a huge effect on all of our thinking," he said.
To Mlodinow, there is almost no such thing as a purely conscious, objective decision. "We have unconscious modules in parts of our brain that are inaccessible to our conscious thought, explicitly inaccessible, that are feeding into all of our conscious though processes," he said.
Mlodinow gave an example of this: The amount of energy your muscles spend if you're running a race, compared to lazing on a couch, goes up by a factor of 100 percent. The energy difference your brain expends concentrating on a tough chess game versus sitting on a couch mindlessly is only about one percent.
"Your brain is always at work, even if you think you're not at work," he added.
The unconscious has its purpose – to help deal with the external, physical world quickly and smoothly, with intuition.
"The difference with humans is that humans are the most social of any species," Mlodinow continued. "So we have a component of our unconscious mind that is analogous to the point that does, for instance, visual processing. It helps you have a clear picture of the world. It's a social unconscious that helps us have a social picture of the world, and it feeds in data we're not aware that we're taking in."
Say you're a swing voter, on the fence about which candidate to choose for in an upcoming election. Mlodinow said that people try to decide based on various data, but they probably don't realize they also factor in peoples' faces unconsciously, looking for whether or not the candidate looks confident, for example.
"In humans, it's actually a very important way that we judge not just peoples' competence, but peoples' character, their emotions, you look at their body language ... it's nonverbal communication," he said.
Though Mlodinow said he recognizes the hazards of unconscious categorizing turning into bias and stereotyping, he said humans can't live without the function.
"It's important to realize that categorization is crucial to our surviving and getting along in the world. If you're getting on a bus, you don't analyze the person behind the wheel to understand that it's a bus driver, you just understand automatically based on the category," he said.
Listen to author Leonard Mlodinow read an excerpt from his book:
Leonard Mlodinow, author of “Subliminal: How Your Unconscious Mind Rules Your Behavior” (Pantheon Books). He teaches at Caltech.