From Amazon:

A mix of popular psychology and trivia, You Are Now Less Dumb is grounded in the idea that we all believe ourselves to be objective observers of reality–except we’re not. But that’s okay, because our delusions keep us sane.

Expanding on this premise, McRaney provides eye-opening analyses of seventeen ways we fool ourselves every day, including:

• Enclothed Cognition (the clothes you wear change your behavior and influence your mental abilities)
• The Benjamin Franklin Effect (how you grow to like people for whom you do nice things and hate the people you harm).
• Deindividuation (Despite our best intentions, we practically disappear when subsumed by a mob mentality)
• The Misattribution of Arousal (Environmental factors have a greater effect on our emotional arousal than the person right in front of us)
• Sunk Cost Fallacy (We will engage in something we don’t enjoy just to make the time or money already invested “worth it”)

McRaney also reveals the true price of happiness, and how to avoid falling for our own lies. 

Motivated reasoning leads to stating your opinion as if it were a proven fact. The more explanation we hear, and the better the story, the more we are willing to accept narratives. We tend to ignore odds and judge the likelihood of something based on how similar an example is to an imagined archetype.

A belief is not more likely to be accurate because many people share it. What is popular is not always good or true. Once you believe something, you’re not very likely to be seeking out evidence to the contrary.

The Benjamin Franklin Effect. You grow to like people for whom you do nice things and hate people you have hurt. The things you do frequently create the things that you believe. Also, the things you buy may influence you to become a sort of person who owns them.

Cognitive dissonance: We often make our view of the world fit with how we feel or what we have done. The higher the price you have paid for your decisions, the more you value them.

The affect heuristic is related to the halo effect. We often rely on our emotions more than on concrete information when making decisions.
Studies seem to indicate that we view beautiful people as more intelligent, strong people as more noble; and friendly people as more trustworthy. It was theorized that after years of having received special treatment as though they had many positive attributes, beautiful people tend to believe and act as if they had those attributes. When beautiful people let you down, you may be more likely to forgive them. In our court system, appearance may affect the length of the sentence a person deemed guilty receives. 

Deindividuation is the perceived loss of individuality and personal responsibility that can occur when someone participates as part of a group; it can lead to pro-social as well as anti-social behaviors. The more you feel personal accountability, the more restraint you will show.

There is a limit to our willpower/self-control. Modern life requires more self-control than ever. If you want to exert more self-control: plan ahead; get more sleep; take breaks; stay fresh. It is recorded that we avoid making important decisions on an empty stomach.