The Great Mental Models, Volume 2: Physics, Chemistry and Biology

by Shane Parrish

Specialized invention, in contrast, focuses on catering to a smaller niche. The advantages of this are that once you own the niche, you are incredibly hard to dislodge.

Your invention fills the niche so completely, there is very little incentive for anyone to invest in developing a competing product. Your growth is capped, but as long as the environment remains stable, as long as there is a continued need for your invention, you have significantly less competition to deal with than the generalists.

if scientists discover a new nectar-producing plant, they can also predict the existence of an insect specially evolved to feed from it, even if said insect hasn’t been discovered yet. If there’s a keyhole, there’s also a key somewhere that fits it.

When human beings are faced with imminent danger, this mechanism kicks in with the mobilization of the sympathetic nervous system. The results in the body are a sharp increase in blood sugar levels, constriction of blood vessels, increase in heart rate, and the diversion of blood from nonessential organs to heart and skeletal muscles.

A core component of self-preservation for all organisms is ensuring access to the resources necessary to survive. This manifests as territorial behavior. An organism or population’s territory is loosely defined as the geographical region containing both the resources it needs to survive and the mating opportunities needed to ensure the survival of its species.

Our skin cells flake off by the millions every day, yet through our lives we never run out. That’s because there are skin cells making copies of themselves all the time. This ability to make perfect copies is built into their structure, and without it we wouldn’t last very long.

This type of replication is called mitosis. It refers to the entire process of replication of nonsexual cells, the result being two genetically identical daughter cells. Mitosis is the process that gives us more skin, more hair, more nails.

You need three things for replication to occur: A code that represents what you wish to replicate, A means of copying this code, And a place to process the code and construct the replication.

Replication is useful beyond skin cells. It has another amazing property—combination. Replications don’t have to be exact copies. The components of cells can be combined in new ways to give us unique instances of existing things. This is sexual reproduction, and it creates new opportunities. Called meiosis,

sex cell contains a copy of half a female’s chromosomes and is combined with half a male’s chromosomes to produce a new whole. The offspring of these parents are genetically unique due both to having two sources for their genes and from variation that occurs in the copying.

It’s not enough just to copy; there also need to be innovations and improvements to compensate for the errors that are inevitably introduced.

Closed systems, those without any new inputs, die in changing environments.

How do you hit the sweet spot between execution of strategy and flexibility to adapt to changing conditions? There are four elements of commander’s intent: formulate, communicate, interpret, and implement.

commander. In order to develop these skills commanders must consider four criteria: Explain the rationale (not just the what and why, but how they arrived at a decision) Establish operational limits (identify what is completely off the table) Get feedback often (a continuous loop between levels) Recognize individual differences (the unique psychological makeup of each subordinate)

What is it about tea that allowed it to be replicated all over the globe? For starters, tea has an inherent flexibility. There are multiple ways to make and consume tea, which can be modified based on cultural norms and social desires. Different degrees of oxidization of tea leaves will produce green, oolong, or black tea. Each of these can flavored with different spices or milk, or whatever else is locally available. It lends itself to different brewing techniques based on local equipment and resources.

Just because something has worked for a while doesn’t mean that it will continue to be effective in perpetuity. Maintaining a successful approach requires an ability to grow and modify that approach as required.

Cooperation significantly expands what’s possible, by creating emergent properties that have more power than the individual components.

when you don’t have time to evolve in response to changes in the environment, cooperation can significantly improve your chances of survival by pursuing relationships that bring mutual benefit.

Cooperation led to the powerful brains we have, capable of art and abstract thinking.

Robin Dunbar, an evolutionary anthropologist, argues that there is a limit to the number of people with whom one can maintain stable social relationships. This limit, of about 150 persons, is set by our neocortex size.

Dunbar suggested that there was a direct correlation between the number of neocortical neurons and the number of social relationships that can be monitored.

Hierarchies in the human world act as information filters causing us to potentially miss opportunities and ideas.

Good leadership is about acting in the interests of the group.

“When it comes to competition, most people believe that the leader of a team is the person who does something spectacular when the chips are down.”16 This, however, is actually not true.

great captains apply to the dynamics of the miners in Chile. “The great captains lowered themselves in relation to the group whenever possible in order to earn the moral authority to drive them forward in tough moments. The person at the back, feeding the ball to others, may look like a servant—but that person is actually creating dependency.

The easiest way to lead, it turns out,...

“leads his men into battle like a man climbing to a height and kicking away the ladder.”1 When you can’t go back, your motivation is to go forward together.

An incentive is a bullet, a key: an often-tiny object with astonishing power to change a situation.

Humans don’t like cognitive dissonance—“the state of tension that occurs whenever a person holds two cognitions (ideas, attitudes, beliefs, opinions) that are psychologically inconsistent.”

“A general ‘law of least effort’ applies to cognitive as well as physical exertion. The law asserts that if there are several ways of achieving the same goal, people will eventually gravitate to the least demanding course of action.

the economy of action, effort is a cost, and the acquisition of skill is driven by the balance of benefits and costs. Laziness is built deep into our nature.”4