How many people do you maintain relationships with? I just checked a few places. I have:
- 91 Facebook "friends"
- 109 LinkedIn "contacts"
- 340 Named "face albums" in Picasa
Robin Dunbar studied social networks in a range of primates, including humans. Our brain's neocortex is primarily responsible for keeping our social network in order: where we are on the status ladder, whom we owe favors to, who owes us, and so forth. The human neocortex is about five times the volume of a chimp's. Chimpanzee social networks tend to top out at 30, the largest size of a stable troop. Apes and monkeys with smaller brains have smaller social networks.
Do I have an exceptional memory, to be able to put names to 340 faces from my photo archive? Not really. The Dunbar Number doesn't express the size of my lifetime "Rolodex", but the largest number of people the average human can afford to spend time maintaining a relationship with. I don't read every post that shows up in my Facebook news feed. There are about 40 FB "friends" that I actively keep track of. When I am not at my computer, my social network breaks down this way:
- 45 church members, all of whom I contact frequently
- 16 people at work, in two work groups
- 15 close relatives and in-laws
- 10 next-door, back-door, or across-the-street neighbors
All this rumination was triggered when I learned of the Dunbar Number in Chapter 26 of David McRaney's new book, You are Not so Smart. The cover blurbs declare, "Why you have too many friends on FaceBook, why your memory is mostly fiction, and 46 other ways you are deluding yourself". True to the promise, the book consists of 48 chapters about the various mental fallacies we all fall prey to. The Dunbar Number is not so much a fallacy as a way to check whether we've perhaps been too greedy in collecting FB friends or Twitter feeds to follow. (By the way, feel free to "follow" this blog. I don't Tweet).
And speaking of blogs, the book is a published embodiment of McRaney's blog. Curiously, when I looked at his list of "all posts", there were 29 items, so he has done some research outside the confines of what he has posted. It also means, you won't actually find everything on the blog, you gotta get the book! Clever dude.
A number of the items he discusses are things we tend to mistake when we don't take time to think. For example, Chapter 25 is titled "The Affect Heuristic", and an example runs like this: Suppose you are offered the chance to get cash for picking red beans out of one of two bowls. Bowl A is huge, with hundreds of beans, many of which are red, while bowl B is much smaller, containing, you are told, a total of 50 beans. The odds are also given: 7% red in the big bowl, and 10% red in the small bowl. You will be given a dollar for each red bean you pick. Most people instinctively select the larger bowl, which the author declares is a fallacy because the odds are against you. But there are two questions I would ask before agreeing to take the challenge. Firstly, how many times can I pick?, and secondly, can I look while I pick? The resulting analysis goes this way:
- One or a few picks (ten or less), and you can't look. Choose the smaller bowl.
- As many picks as you like (or at least 25), whether you can look or not. Choose the larger bowl.
For others, it seems we are hard-wired a certain way, and quite unlikely to beat the wiring. For instance, there is the Anchoring Effect (Chapter 39). You see something you'd really like, but the price is too high. You wait for a sale. The sale day comes, and you go to have a look. It is marked down by half, but you were hoping for an even lower price. When you begin to leave, an alert clerk offers you another $5 off, and you take it. Did you get a good deal? If it was a Louis Vuitton purse or a leather bomber jacket, initially priced at $800, then marked down to $400, was $395 a good deal? Only if you are accustomed to that lifestyle. Even if you know the price of production is $75, the status may be worth it to you. That's what the premium brand retailers count on. The $800 was an "anchor" to set your expectation, so that $395 seems like a bargain. You can get a great purse that will last you for years and looks good at an outlet store for $60 or less. Ditto a bomber jacket. It just won't have the premium label (unless you buy a counterfeit label online and sew it on yourself). You can take advantage of anchoring, whenever you initiate a negotiation. Start with an unreasonably extreme position, and put the other person in the position of bargaining with you.
The book is full of revealing essays, and nearly all spend a bit of time discussing psychological research that underlines the point. Why do we fall prey to so many fallacies? We are more complex than we think. We have a strong emotional life, which evolved long before the "intellectual" part of the brain. For millions of years, quick recognition, snap judgments, and rapid heuristics saved the lives of our ancestors so they could have descendants. If you had to calculate the weight of that tiger (let's see, nine feet long and two feet wide, so he's a cylinder, and the formula is pi r squared times length, times 64 pounds per cubic foot) before deciding to jump, you'd be tiger food every time. Maybe Spock could tell you how heavy the tiger is, while both of you are running for your lives. I still haven't got it figured out (my calculator just told me: 1,809 pounds. Oh, well; real tigers weigh 500-700 pounds). Our logical, intellectual life is only useful when we have leisure to take advantage of it. Anchoring may be a useful trait when choosing which of two cliffs to jump off; you'll always choose the lower one, and you'll be right. It just doesn't translate well into a retail setting, unless you are the retailer!
It takes a bit of humility to read this book, but that won't hurt. Many of our follies are undergirded by the tendency we all have to overestimate ourselves. Something like 80% of drivers say they drive better than average. The definition of average guarantees that only 50% (minus 1) can be above average. And before someone asks, "That's only true if 'average' means 'median'!", I agree. Because that is what I meant. Driving skill can be ranked but not quantitatively scored, so median is the only average that is possible.
I learned a few things that may help me. Chances are I'll forget most of it, though. I pride myself on a good memory, but 48 informal fallacies? Beyond me. It was a fun read, though.