So, if you are able to do things to induce cognitive ease in people you are more likely to get them to do things in your favour (the book does cover a few ways to improve cognitive ease, such as getting people to smile).On the contrary, when you are in a state of cognitive strain you are more likely to be more vigilant and suspicious, invest more in what you are doing, feel less comfortable and generally make lesser mistakes but are also less creative / intuitive. You are also likely to be relatively superficial and casual in your thinking. Cognitive ease and strain: When you are in a state of cognitive ease, you a probably in a good mood, like what you see, believe what you hear, trust your intuitions and feel that your current situation is comfortably familiar.Its often the latter that gets compromised more. S2 itself might itself be divided into two 'parts': One for 'intelligence' and the other for 'rationality'.Exertion of self-control depletes S2, getting in flow state/meditation might help restore. If you know your S2 is compromised, don't be in tempting/risky situations. indulging in beer after a hard day at work or having chocolate cake for breakfast after a sleepless night or resorting to 'standard procedure' instead of thinking through the problem. Be on-guard when you know your S2 is 'depleted': As S1 has more influence over behaviour when S2 is tired/busy elsewhere/overwhelmed.binary) about things, while S2 can be analogue (i.e. But S1 still managed to stick around because life likes to be economical about energy usage and S2 is energy hungry, so in places where stakes are routine/not high then S1 provides an energy efficient (and much faster) alternative to using S2.

S2 probably came second and because it provides an evolutionary advantage of conscious planning and forecasting.

S1 likely came (developed) first and with the right 'heuristics' allowed certain species to survive and pass on those traits.

S2 is in charge of conscious behaviour and one of its jobs is to overcome S1's impulses. S1 takes over in emergencies and assigns total priority to self-protective actions.The invisible gorilla is an amusing example. S2 requires attention, we have a limited store: Hence we fail at/find it extremely difficult to focus on more than one activity at once.When S1 encounters something it does not have a ready answer to, it calls on S2 (e.g.S1 suggests things to S2 and if it all goes smoothly then S2 accepts S1's suggestions with no/little modification. S1 runs automatically (and cannot be turned 'off') and S2 is usually in a 'low effort' mode (and can be turned 'off').These two systems work together and system 1 often hands off more complex/novel experiences to system 2 to 'look at'. System 2 (S2) is effortful and requires conscious allocation of attention (and is interrupted when attention is interrupted). We have two systems, 1 and 2: System 1 (S1) operates automatically without little conscious effort.We humans, we really like to hang on to what we think we already have. Loss aversion: We will often make irrational decisions so that we can just avoid the uncomfortable feeling of having lost something.Availability: We are lazy and, unless checked, will make decisions based on information that is readily available erroneously assuming it to be all there is and not seeking additional information or even entirely ignoring competing information.

Framing: How a situation is presented (to us or to others) can lead to very different outcomes in how it is interpreted by and subsequently acted upon by people.While the book talks through many concepts and cites relevant examples, I found that most of them can be categorized under: This book is a treasure trove of knowledge on psychology and biases, and my cherry-picked ideas below do not do it justice, if you are interested in the subject then do read the book for yourself. This is of course, a well-known book, so you might already know it's about how humans make decisions and how we can identify certain systems at play that can impact decision making (and correct for them if required).

Thinking fast and slow