Most people stop at the first layer of cause and effect. But second-order thinkers trace the chain two or three steps further, catching hidden consequences that first-order thinkers miss entirely and later regret ignoring.

To practice, take any decision and ask three times: "And then what?" Write down each layer. You will often find that the obvious first move sets off a chain reaction that reverses the intended benefit two steps later. The further ahead you trace, the harder it is to be blindsided.