Book Summary: “Social Physics: How Social Networks Make Us Smarter” by Alex Pentland

Social Physics

Title: Social Physics: How Social Networks Make Us Smarter
Author: Alex Pentland
Scope: 3.5 stars
Readability: 3 stars
My personal rating: 4 stars
See more on my book rating system.

If you enjoy this summary, please support the author by buying the book.

Topic of Book

The author applies the concept of Social Physics to try to identify what makes creative people creative.

If you would like to learn more about how social networks created the modern world, read my book From Poverty to Progress: How Humans Invented Progress, and How We Can Keep It Going.

Key Take-aways

  • Creative people are rarely genius hermits working isolated in a lab.
  • Creative people spend a great deal of time seeking out new people with differing ideas. They bounce their ideas of those people and learn from their differing viewpoints. This enables creative people to gradually hone their ideas to something that might work.
  • Only after testing their ideas on a wide variety of people, do creative people move towards implementing their ideas.
  • Trust is the glue that makes social networks function. Without trust, creative people cannot thoroughly explore their ideas before implementing them.

Important Quotes from Book

“What I have learned from these experiences is that many of the traditional ideas we have about ourselves and how society works are wrong. It is not simply the brightest who have the best ideas; it is those who are best at harvesting ideas from others. It is not only the most determined who drive change; it is those who most fully engage with like-minded people. And it is not wealth or prestige that best motivates people; it is respect and help from peers.”

“Most people think about using a framework centered on the individual and the eventual steady-state outcome, whereas I think in terms of social physics: growth processes within networks.”

“It posits social learning and social pressure as primary forces that drive the evolution of culture and govern much of the hyper-connected world”

The two most important concepts in social physics:

  • Idea flow within social networks, and how it can be separated into exploration (finding new ideas/strategies) and engagement (getting everyone to coordinate their behavior).
  • Social learning, which is how new ideas become habits, and how learning can be accelerated and shaped by social pressure.

“The most consistently creative and insightful people are explorers. They spend an enormous amount of time seeking out new people and different ideas, without necessarily trying very hard to find the “best” people or “best” ideas. Instead, they seek out people with different views and different ideas.

Along with this continuous search for new ideas, these explorers do another interesting thing: They winnow down their most recently discovered ideas to the best ones through their habit of bouncing them off of everyone they meet—and remember that they meet many different sorts of people. Diversity of viewpoint and experience is an important success factor when harvesting innovative ideas. The ideas that provoke reactions of surprise or interest from a wide range of people are the keepers. These are the ideas that are harvested, assembled into a new story about the world, and used to guide actions and decisions.

The most productive people are constantly developing and testing a new story, adding newly discovered ideas to the story and then trying it out on everyone they meet.

Finally they decide that it is time to act on it, to bring it into the light and test it against reality. To these people, the practice of harvesting, winnowing, and sculpting with ideas feels like play. In fact, some of them call it “serious play”.

“It seems that the key to harvesting ideas that lead to great decisions is to learn from the successes and failures of others and to make sure that the opportunities for this sort of social learning are sufficiently diverse.”

The wisdom of the crowd resides in between the extremes of isolation and the herd behavior seen when the social network is an echo chamber. This intermediate zone is where social learning, that is, copying successful people, yields real rewards.”

 “People’s decisions are a blend of personal information and social information, and when the personal information is weak, they will tend to rely more on social information.”

 “Exploration is the part of idea flow that brings new ideas into a work group or community… Social learning is critical: Copying other people’s successes, when combined with individual learning, is dramatically better than individual learning alone. When your individual information is unclear, rely more on social learning.”

“Diversity is important: When everyone is going in the same direction, then it is a good bet that there isn’t enough diversity in your information and idea sources, and you should explore further. A big danger of social learning is groupthink.”

“Contrarians are important: When people are behaving independently of their social learning, it is likely that they have independent information and that they believe in that information enough to fight the effects of social influence. Find as many of these “wise guys” as possible and learn from them. Such contrarians sometimes have the best ideas, but sometimes they are just oddballs. How can you know which is which? If you can find many such independent thinkers and discover that there is a consensus among a large subset of them, then a really, really good trading strategy is to follow the contrarian consensus. For instance, in the eToro network the consensus of these independent strategies is reliably more than twice as good as the best human trader.”

“In summary, people act like idea-processing machines combining individual thinking and social learning from the experiences of others. Success depends greatly on the quality of your exploration and that, in turn, relies on the diversity and independence of your information and idea sources.”

“As Nobel Laureate Daniel Kahneman might have put it, we can consciously reason about which flow of ideas we want to swim in, but then exposure to those ideas will work to shape our habits and beliefs subconsciously.”

“Perhaps this is because learning from surrounding example behaviors is much more efficient than learning solely from our own experiences. Mathematical models of learning in complex environments suggest that the best strategy for learning is to spend 90 percent of our efforts on exploration, i.e., finding and copying others who appear to be doing well. The remaining 10 percent should be spent on individual experimentation and thinking things through.

The logic behind this is simple: If somebody else has invested the effort to learn some useful behavior, then it is easier to copy them than to think it through all over again.”

“For factual beliefs (e.g., “The dinner starts at 7:00 P.M.”), a single exposure from a trusted peer is usually sufficient to convert a person to that belief. In contrast, to change habitual behaviors, preferences, and interests, it usually requires several exposures within a short period of time. For instance, if everyone in a work group starts drinking green tea rather than coffee, the odds are good that others will pick up the green tea habit as well. Multiple exposures showing that a new behavior has a good outcome (such as social approval) are needed before we are likely to pick up the habit as our own.

My experiments suggest that the continual exploratory behavior of humans is a quick learning process that is guided by apparent popularity among peers. In contrast, adoption of habits and preferences is a slow process that requires repeated exposure and perceptual validation within a community of peers. Our social world consists of the rush and excitement of new ideas harvested through exploration, and then the quieter and slower process of engaging with peers in order to winnow through those ideas, to determine which should be converted into personal habits and social norms.

Over time we develop a shared set of habits for how to act and respond in many different situations, and these largely automatic habits of action account for the vast majority of our daily behavior.”

“Using the terminology of economics, in most things we are collectively rational, and only in some areas are we individually rational”

“The collective intelligence of a community comes from idea flow; we learn from the ideas that surround us, and others learn from us. Over time, a community with members who actively engage with each other creates a group with shared, integrated habits and beliefs. When the flow of ideas incorporates a constant stream of outside ideas as well, then the individuals in the community make better decisions than they could on their own”

“So even though today’s society tends to glorify the individual, the vast majority of our decisions are shaped by common sense, the habits and beliefs we have in common with our peers, and these common habits are shaped by interactions with other people. We learn common sense almost automatically, by observing and then copying the common behaviors of our peers. It is through these collective preference and decision mechanisms that we come to automatically behave politely at parties, respectfully at work, and passively in public transit. It is the idea flow within a community that builds the intelligence that makes it successful.”

“Average performers thought teamwork meant doing their part on the team. Star performers, however, saw things differently: They pushed everyone on the team toward joint ownership of goal setting, group commitments, work activities, schedules, and group accomplishments. That is, star performers promoted synchronized, uniform idea flow within the team by making everyone feel a part of it and tried to reach a sufficient consensus so that everyone would willingly go along with new ideas.

Synchronization and uniformity of idea flow within a group is critical: When an overwhelming majority seem ready to adopt a new idea, this convinces even the skeptics to go along. A surprising finding is that when people are working together doing the same thing in synchrony with others—e.g., rowing together, dancing together—our bodies release endorphins, natural opiates that give a pleasant high as a reward for working together.”

“to effectively change a habit requires several examples of trusted peers successfully using or recommending a new idea within a short period of time.”

“Because trust is the expectation of future cooperative behavior and is based on previous interactions, people seem to operate by what I call the reverse golden rule: Do unto others as they have done to you. This is similar to the tit-for-tat strategy that is often seen in trust games, such as the classic prisoner’s dilemma problem, but now applied as a general, default strategy.

Unfortunately, people quickly learn to apply this rule differently with peer groups versus with others; that is, trust peers and don’t trust the others.”

“As with the concept of exploration, there are three key things to remember about engagement:

  • Engagement requires interaction: If people are to work together efficiently, there needs to be what is called network constraint: repeated interactions between all of the members of the group—not just between a leader and the members, or between the members and the entire group (as at a group meeting).”
  • Engagement requires cooperation:
  • “Building trust: Trust, by which I mean the expectation of future fair, cooperative exchanges, is built from the history of exchanges between people. Consequently, social networks have both history and momentum.”

“What these sociometric data showed was that the pattern of idea flow by itself was more important to group performance than all other factors and, in fact, was as important as all other factors taken together. Think about it: Individual intelligence, personality, skill, and everything else together mattered less than the pattern of idea flow.

Wen and I found that three simple patterns accounted for approximately 50 percent of the variation in performance across groups and tasks. The characteristics typical of the highest-performing groups included: 1) a large number of ideas: many very short contributions rather than a few long ones; 2) dense interactions: a continuous, overlapping cycling between making contributions and very short (less than one second) responsive comments (such as “good,” “that’s right,” “what?” etc.) that serve to validate or invalidate the ideas and build consensus; and 3) diversity of ideas: everyone within a group contributing ideas and reactions, with similar levels of turn taking among the participants.”

 “The central reason exchange networks are better than markets is trust. Relationships in an exchange network quickly become stable (we go back again and again to the person who gives us the best deal), and with stability comes trust, i.e., the expectation of a continued valuable relationship.”

 “Our results strongly suggest that the invisible hand is more due to the trust, cooperation, and robustness properties of the person-to-person network of exchanges than it is due to any magic in the workings of the market. If we want to have a fair, stable society, we need to look to the network of exchanges between people, and not to market competition.”

“Egalitarian and stable, though, does not necessarily mean peaceful. Some of them were very violent, with intertribal warfare playing a very significant role in determining both life expectancy and mixing of the gene pool. I believe that this violence is, at its heart, due to very low levels of idea flow: high levels of engagement within a community combined with low levels of exploration outside the community usually leads to rigid and insular societies. Insular communities (including the society of Adam Smith) often inflict terrible damage on weaker communities with whom they share resources,”

“Even though we now have much greater breadth and rate of interaction, our habits still depend mostly on interactions with a few trusted sources—those people whom we interact with frequently—and for each person the number of such trusted individuals remains quite small. In fact, the evidence is that the number of trusted peers that we have today is pretty much the same as it was tens of thousands of years ago.

If you would like to learn more about how social networks created the modern world, read my book From Poverty to Progress: How Humans Invented Progress, and How We Can Keep It Going.

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