You have 12 black socks and 12 white socks mixed up in a drawer. You’re up very early and it’s too dark to tell them apart. What’s the smallest number of socks you need to take out (blindly) to be sure of having a matching pair?
Three socks. If the first sock is black, the second one could be black, in which case you have a matching pair. If the second sock is white, the third sock will be either black and match the first sock, or white and match the second sock.
Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.
Which is more probable?
1) Linda is a bank teller. 2) Linda is a bank teller and is active in the feminist movement.
Most people guess number two, but the probability of two events occurring together is always less than or equal to the probability of either one occurring alone. This problem is known as the Conjunction Fallacy.
The magic word – please. It makes people do things they otherwise wouldn’t be inclined to do. When parents are teaching children about manners, they call it the magic word and wait to fulfill a request until the child says please. Once the child says it, the parent feels bound to do it to show the child that it works.
