Quotes from Nicholas A. Christakis

When a disease is very deadly, it kills its victims so rapidly that the pathogen does not have much time to spread. This is why the super-deadly Ebola epidemics that kindle in Africa every few years tend to burn out.

Singapore Health Department in April, for example, I was astonished to learn that they employed five thousand contact tracers in a population of about five million people. One person per thousand in their whole nation was employed for this purpose alone. At the time, Singapore had accumulated just 9,125 cases. In our country, this would translate into having 330,000 people engaged in this work.

Closing the schools can harm children who are neglected or unsafe at home and who benefit from the caring eyes of a teacher.

An analysis in South Korea showed that outbreaks were more common in Zumba classes than Pilates classes for a similar reason.49 Heavy, rapid, deep breathing or shouting may be a risk factor for transmission, whereas slow, gentle breathing is not. But being indoors itself plays an important role.

The challenges communes faced were generally internal, not external. As one study concluded, "Many more communes went under because the dishes never got washed than were ever forced out of town by hostile neighbors or zoning boards.

The arc of our evolutionary history is long. But it bends towards goodness

the wearing of masks reflects altruism,

corruption of the mind" was much more dangerous during an epidemic than "any such miasma and vitiation of the air which we breathe around us.

In his classic work Extraordinary Popular Delusions and the Madness of Crowds, published in 1841, Scottish journalist Charles Mackay argued that people "go mad in herds, while they only recover their senses slowly, and one by one."1 People in crowds often act in thoughtless ways—shouting profanities, destroying property, throwing bricks, threatening others.

Vi blir faktiskt mer ledsna när våra familjemedlemmar är ledsna än om främmande människor är ledsna.

P]å både individ- och gruppnivå är det mer effektivt att gå ner i vikt tillsammans med sina vänners vänner än tillsammans med sina vänner. Problemet är detta: Om du försöker gå ner i vikt tillsammans med dina vänner så är det mycket möjligt att du lyckas, men det pyttelilla klustret som består av dig och dina vänner är omgivet av en stor grupp människor som utövar påtryckningar för att ni ska gå upp i vikt igen.

Alla har upplevt känslomässig överföring... . Men en ofta förbisedd aspekt av all denna överföring av känslor är att de inte bara sprider sig till våra vänner utan också till våra vänners vänner och ännu längre - även om vi inte ens är närvarande.

Ett val som bygger på nätverksteori kan vara sjuhundra gånger effektivare och mer ändamålsenligt [än ett slumpmässigt urval].

A dead host cannot easily spread the germ to others, so causing milder illness is "better" for the pathogen from a Darwinian point of view. People who are very sick stay home in bed or die, and those who are only mildly sick continue with their lives, preferentially spreading milder strains of the pathogen.

we carry within us innate proclivities that reflect our natural social state, a state that is, as it turns out, primarily good, practically and even morally. Humans can no more make a society that is inconsistent with these positive urges than ants can suddenly make beehives.

it is very difficult to totally exclude the possibility of an accidental release of a naturally occurring pathogen that was collected from bats and then taken to the lab for study.

In other words, Americans know they should wash their hands. They just do not translate that knowledge into action. This is particularly true for men. A quantitative assessment of eighty-five scientific studies found that, compared to men, women were better handwashers

Ju fler vänner dina vänner har (oavsett deras känslomässiga tillstånd), desto mer sannolikt är det således att du är lycklig.

Att ha en stor social krets kan alltså göra dig lycklig, men om du är lycklig vidgar det inte nödvändigtvis din sociala krets. En position i mitten av nätverket leder till lycka - inte tvärtom. Ditt nätverks struktur och din plats i det har stor betydelse.

The fundamental reason is that we each carry within us an evolutionary blueprint for making a good society.

psychologist David Premack refers to as the "Russian-novel problem"—that is, when looking at the history of two animals (or humans), it is often hard to know what caused what, since the two may have interacted in so many ways over such a long time, and they may also remember events differently and act according to this subjective experience.

the perplexing fact that when Europeans came into contact with American Indians, the transfer of deadly germs was all one way (with the possible exception of syphilis).12 There were no domesticated animals in the New World (other than the Peruvian llama), which meant humans there had no opportunity to evolve genetic resistance to particular diseases that originated in such animals before circulating among people.

Den modell som bäst kunde förutsäga strukturen i de amerikanska senatorernas nätverk var faktiskt den som beskrev det sociala slickandet hos kor.

I själva verket är det så att den individuella lyckan verkar vara starkt genetiskt betingad, precis som alla andra personlighetsdrag.