Repost­ed from the old TfK, while I Trav­el from Kansas.

Every­one is answer­ing Seed’s Ques­tion of the Week: If you could shake the pub­lic and make them under­stand one sci­en­tif­ic idea, what would it be?

I’m down with this answer:

I want peo­ple to under­stand that there is no law of aver­ages. There are no laws of prob­a­bil­i­ty (at least not if you mean some­thing like “Real­ly improb­a­ble things don’t hap­pen”). You can’t prove just any­thing with statistics.

My incli­na­tion would actu­al­ly have been phrased the exact oppo­site way, though get­ting at the same point.

It’s true that there’s no law which says that a head is more like­ly when you’ve flipped sev­er­al tails in a row, there are indeed laws of prob­a­bil­i­ty. They belong to a whole class of things which many peo­ple have a lot of trou­ble with: emer­gent properties.

Emer­gent prop­er­ties rely on large num­bers and often on inter­ac­tions between sim­ple agents. Out of that large num­ber of inter­ac­tions, com­plex and often pre­dictable results emerge. A prob­a­bil­i­ty or an aver­age is a very sim­ple emer­gent prop­er­ty of a sys­tem. Bio­log­i­cal fit­ness can be expressed as such a sim­ple prob­a­bil­i­ty. Nat­ur­al selec­tion is a result of mul­ti­ple organ­isms with dif­fer­ent fit­ness­es inter­act­ing with an envi­ron­ment, and the trend we can find in nat­ur­al selec­tion — its pre­dic­tive capa­bil­i­ty — is also an emer­gent process.

Evo­lu­tion is a com­bi­na­tion of nat­ur­al selec­tion and a num­ber of prob­a­bilis­tic (and there­fore emer­gent) process­es, all of which com­bine to pro­duce the com­plex sys­tem of life on Earth that we know.

An organ­is­m’s life is itself an emer­gent prop­er­ty of the suc­cess­ful inter­ac­tions of numer­ous cells, each of which has numer­ous inter­act­ing mol­e­c­u­lar agents with­in it. The mind can be seen as an emer­gent process of the neu­rons in the brain. Indi­vid­ual neu­rons fol­low very sim­ple rules, but it seems that when you get enough of them togeth­er, tru­ly won­drous things emerge.

Anthills and ecosys­tems are emer­gent process­es, too.

Most of the chal­lenges we face in mod­ern soci­ety relate to our abil­i­ty to man­age the com­plex­i­ty of these sorts of process­es. Often as not, there is a prob­a­bilis­tic com­po­nent to these process­es, which requires that we appre­ci­ate the real laws of prob­a­bil­i­ty. The extinc­tion of one species, a small change in car­bon diox­ide emis­sions, or the accu­mu­la­tion of numer­ous small muta­tions can have dra­mat­ic effects, and those effects are pre­dictable and under­stand­able when we appre­ci­ate how the emer­gent process works.

When con­front­ed with these sorts of sit­u­a­tions, most peo­ple just get hung up on the com­plex­i­ty. The atmos­phere is a com­plex, feed­back dri­ven sys­tem. Emer­gence tells us that pre­dictable sim­plic­i­ty can arise from such sys­tems, and that’s why cli­mate mod­el­ers can do their work and pro­duce a basic agree­ment about the effects of ris­ing car­bon diox­ide. If more pol­i­cy-mak­ers appre­ci­at­ed that, we might be clos­er to con­trol­ling that change.

Evo­lu­tion is com­pli­cat­ed. It’s built around the com­plex­i­ty of each organ­ism, and a com­plex set of unpre­dictable changes in the envi­ron­ment and the organ­is­m’s genet­ic code. But out of those numer­ous inter­ac­tions, a pre­dictable process emerges. If more biol­o­gy teach­ers, let alone par­ents, school boards and vot­ers, appre­ci­at­ed how evo­lu­tion emerges from that com­plex­i­ty, a lot of the cre­ation­ism bat­tles would go away.

Lack of appre­ci­a­tion of emer­gence is behind many divi­sive social issues of the day, and if I could shake that into a few more minds, I’d be a hap­py man.