When do you look something up, and when do you try to remember it?  One of the hallmarks of humans is our ability to store and access information in the environment around us as well as in our own central nervous systems. We have an external memory and an internal memory. Many tasks involve moment-to-moment trade-offs between the two. The “soft […]

What’s the capital of Burkina Faso? Which bird can fly backwards? What was the first human invention to break the sound barrier? Questions of this type probe what is called “semantic memory”, the repository of our general knowledge, which is known to be organized by meaning rather than by autobiographical cues. For example, you may […]

Anyone who has ever written a book knows how long and arduous the process can be. Anyone who has authored 2 or 3 books should take justifiable pride in their accomplishments. But I know no one who could conceivably author more than 500 books. It sounds preposterous to even think that this many books might […]

Do children misbehave during a full moon? Are Asians “pushy”? Are the members of minority group X particularly prone to alcoholism? People often fall prey to developing such associations even though they are entirely illusory—that is, the actual statistics of the environment warrant no such beliefs. In the laboratory, those illusory correlations are readily evoked […]

Why do people cooperate? Why do we band together in extraordinary numbers to solve problems? Why do we commit acts of “heroism” to protect or save others, including sometimes people we don’t even know personally? The level of cooperation that humans routinely exhibit poses an evolutionary puzzle and an enigma to economists. The essence of cooperation is the fact […]

You are stranded on a desert island or in the grasslands of a foreign country, without food or water or transportation. Your only friend is a volleyball. Somewhat annoyingly, a prescient memory researcher has pinned a list of words to a tree with instructions for you to rate their relevance to your situation. How relevant is […]

It was once thought that what we perceive is a straightforward reflection of a stable reality. So, we see a circle to be a certain size because it is a certain size. A quick glance at illusions such as the Ebbinghaus illusion and the Rubik’s cube color illusion clearly show that this is not the case: what we perceive […]

A picture is worth a thousand words—or is it? How does a pulley work? What about a block and tackle? According to Wikipedia, “A pulley is a wheel on an axle that is designed to support movement and change of direction of a cable or belt along its circumference.” When multiple pulleys are combined together “so […]

There is physics. Then there is psychology. And never the twain shall meet? No, quite to the contrary: The nature of the relationship between the physical world and its psychological representation is among the most studied—and understood—of all mental phenomena. For more than 150 years, psychophysicists have been studying the mapping between physical quantities, such as weight […]