2 . Every decision we make is arrived at through hugely complex neurological processing. Although it feels as though you have a choice, the action that you ‘decide’ to take is entirely directed by automatic neural activity. Brain imaging studies show that a person’s action can be predicted by their brain activity up to 10 seconds before they themselves become aware they are going to act. Multiple neuroscientific studies show that even those important decisions that feel worked out are just as automatic as knee-jerk reactions (膝跳反应) (although more complex).

Decision-making starts with the amygdala: a set of two almond-shaped nuclei (杏仁状核) buried deep within the brain, which generate emotion. The amygdala registers the information streaming in through our senses and responds to it in less than a second, sending signals throughout the brain. These produce an urge to run, fight, freeze or grab, according to how the amygdala values various stimuli.

Before we act on the amygdala’s signals, however, the information is usually processed by other brain areas, including some that produce conscious thoughts and emotions. Areas concerned with recognition work out what’s going on, those concerned with memory compare it with previous experiences, and those concerned with reasoning, judging and planning get to work on constructing various action plans. The best plan—if we are lucky—is then selected and carried out. If any of this process goes wrong, we are likely to hesitate, or do something silly.

The various stages of decision-making are marked by different types of brain activity. Fast (gamma)waves, with frequencies of 25 to 100 Hz, produce a keen awareness of the multiple factors that need to be taken into account to arrive at a decision. If you are trying to choose a sandwich, for instance, gamma waves generated in various cells within the ‘taste’ area of the brain bring to mind and compare the taste of ham, hummus, wholemeal, sourdough, and so on. Although it may seem useful to be aware of the full range of choice, too much information makes decision-making more difficult, so irrelevant factors get dismissed quickly and unconsciously.

After this comparison stage, the brain switches to slow-wave activity (12 to 30 Hz). This extinguishes most of the gamma activity, leaving just a single ‘hotspot’ of gamma waves which marks the chosen option.

Although there is no ‘you’ outside your brain to direct what it’s doing, you can help it to make good decisions by placing yourself in a situation which is likely to make the process run more smoothly. Doing something that is physically or mentally stimulating before making a decision will help your brain produce the initial gamma waves that generate awareness of the competing options. Getting over-excited, on the other hand, will prevent the switch to the slow brainwaves, making it much harder to single out a choice.

8 . On March 7, 1907, the English statistician Francis Galton published a paper which illustrated what has come to be known as the “wisdom of crowds” effect. The experiment of estimation he conducted showed that in some cases, the average of a large number of independent estimates could be quite accurate.

This effect capitalizes on the fact that when people make errors, those errors aren’t always the same. Some people will tend to overestimate, and some to underestimate. When enough of these errors are averaged together, they cancel each other out, resulting in a more accurate estimate. If people are similar and tend to make the same errors, then their errors won’t cancel each other out. In more technical terms, the wisdom of crowds requires that people’s estimates be independent. If for whatever reasons, people’s errors become correlated or dependent, the accuracy of the estimate will go down.

But a new study led by Joaquin Navajas offered an interesting twist (转折) on this classic phenomenon. The key finding of the study was that when crowds were further divided into smaller groups that were allowed to have a discussion, the averages from these groups were more accurate than those from an equal number of independent individuals. For instance, the average obtained from the estimates of four discussion groups of five was significantly more accurate than the average obtained from 20 independent individuals.

In a follow-up study with 100 university students, the researchers tried to get a better sense of what the group members actually did in their discussion. Did they tend to go with those most confident about their estimates? Did they follow those least willing to change their minds? This happened some of the time, but it wasn’t the dominant response. Most frequently, the groups reported that they “shared arguments and reasoned together”. Somehow, these arguments and reasoning resulted in a global reduction in error. Although the studies led by Navajas have limitations and many questions remain, the potential implications for group discussion and decision-making are enormous.

As Hurricane Lan bore down on Florida, many residents who stayed put found themselves unable to leave even if they tried. For hours they were forced to fight heavy winds and attempt to escape flooding inside long-loved homes that had become frightening, deadly traps. Within days, around 100 deaths in the state would be attributed to the hurricane, many of them were older residents who drowned.

When the water slipped in under the door of their home, it was just a glimmer on the floor, a sign that it was time to go. It was Wednesday, Sept.28, around noon, and Bishop woke up her two brothers, who had been resting after lunch. She pulled the wheelchair up to the oldest, Russell, 67. Her other brother, Todd, 63, could manage with a walker.

Both men had been born with cerebral palsy (脑瘫), and their mental development was like that of a young child. About 10 years ago, they started showing signs of Parkinson’s disease. But they found joy in their surroundings. Todd liked collecting cans at the beach. Russell loved riding the bus and going to parks. Bishop, 61, was their lifeline, their little sister who had long felt an obligation to keep them safe.

“We’ve got to get going!” she shouted to them. She went to open the front door. It would not move. The weight of the water on the other side had made it shut. She rushed to try the door to the garage. It, too, was stuck. That’s when the house began to flood. It went from ankle-deep to knee-deep in less than five minutes. Bishop knew that there was no way out.

Now Bishop and her brothers were trapped. At 12:34 p.m., she called 911 but couldn’t get through. There was no one she could get in touch with. To try her fortune, she texted a neighbor, Walters, who was always there when neighbors were in need, “Water’s coming in.” Around her, she could hear the dining room hutch (餐具柜) tipping and crashing, the china breaking, the refrigerator toppling over.

The only way to go was up, so Bishop guided her two bothers to the stairs.

Bishop sank into despair, but she noticed it seemed water stopped coming in.

My middle child, Jake, was smart and good-looking, but he always sees the cup of life as half empty. Every day when he came home from school, Jake would list everything bad that happened that day!

On his ninth birthday, we saved enough money to take the family to Disneyland for two days. His dad and I didn’t make much then, so it cost a considerable amount, but we felt Jake’s birthday was worth it. After doing Disneyland to death (玩够了), we returned to our hotel room, all exhausted. And I asked the birthday boy, “Did you have fun today, Jake?”

All my fault-finding son could say to me was “Pirates (海盗) of the Caribbean was closed!” “Jake Marshall,” I was clearly unable to contain my anger, “we stood in line for an hour and a half to see The Haunted Mansion. We rode Space Mountain three times. We spent two days playing in the park, and all you can say is, Pirates of the Caribbean was closed?” Clearly, something had to be done about his negative attitude and I was going to be the one to do it!

I was determined to help him. I read every article and bought every book. With the help of great resources, I found my son had the tendency to see the worst in every situation. My research told me that people with negativity have an emotional need for order and sensitivity. That meant I needed to listen to my son’s daily pessimistic reports. My usual reaction was to try to talk Jake out of his negativity, but that wouldn’t satisfy his need for sensitivity, so I had to let him finish his complaints and ask what good things happened. Then I needed to wait until he could tell me. This would help Jake realize that good things really were happening to him.