Lefties May Be Biased Toward the Left-Hand Side of the Ballot

Democracy is more subliminal than you think.

National Journal
Brian Resnick
March 25, 2014, 8:20 a.m.

Say it’s Elec­tion Day. Once in­side the booth, a voter feels a pang of anxi­ety. He’s am­bi­val­ent and de­cides to pick a can­did­ate at ran­dom.

The voter is a lefty. And though he may not real­ize it, the hand he writes with has in­flu­enced the can­did­ate he votes for — the one lis­ted on the left side of the booth. When his friends ask him how he voted, he says he guessed. But a sub­lim­in­al bi­as is at play.

In a re­cent ex­per­i­ment pub­lished in the journ­al Polit­ic­al Psy­cho­logy, can­did­ates lis­ted on the left-hand side of the bal­lot en­joyed a 15 per­cent bump among lefties com­pared with right-handed voters. “Righties im­pli­citly think right is good, lefties im­pli­citly think left is good,” says Daniel Cas­as­anto, a coau­thor of the study.

And for such an ar­bit­rary sound­ing reas­on, a race can be won or lost.


What does it say about demo­cracy if elec­tions can be thrown by the sub­lim­in­al quirks of the brain?

It wasn’t a leap for Cas­as­anto to hy­po­thes­ize that left- or right-hand dom­in­ance would in­flu­ence vot­ing be­ha­vi­or. He’s found a sim­il­ar ef­fect be­fore in non­polit­ic­al set­tings. In one such ex­per­i­ment, he showed par­ti­cipants pairs of ali­en draw­ings called Fribbles, and asked how in­tel­li­gent, hon­est, at­tract­ive, and happy they were — strange ques­tions when you con­sider that a Fribble looks like this. The lefties re­spon­ded more kindly to the ali­ens on the left, the righties more kindly to those on the right.

“Our bod­ies are an ever-present part of the con­text in which we use our minds, and should there­fore ex­ert a per­vas­ive in­flu­ence on the rep­res­ent­a­tions we tend to form,” Cas­an­anto writes. Ac­cord­ing to that the­ory, what’s true for the ali­ens should be true of politi­cians.

And it was. In an ex­per­i­ment­al elec­tion of two hy­po­thet­ic­al can­did­ates, each di­ver­ging on is­sues and each ran­domly sor­ted in­to a left or right spot on the bal­lot, “every­one, even righties, had a bi­as to se­lect the can­did­ate on the left, but that tend­ency was stronger in lefties,” Cas­as­anto says.

Some of the many con­tro­ver­sial 2000 pres­id­en­tial elec­tion bal­lot boxes and vot­ing booths sit in stor­age on Nov. 6, 2001, in Palm Beach, Fla. How might have the world been dif­fer­ent if Al Gore was lis­ted first?  (Joe Raedle/Getty Im­ages)

Let’s back up a bit.

Cas­as­anto’s re­search at­tempts to an­swer the “why” to one of the more con­found­ing phe­nom­ena in demo­cracy: the primacy ef­fect, which is the tend­ency of can­did­ates lis­ted first on the bal­lot to re­ceive more votes than they would if they were lis­ted later.

A forth­com­ing pa­per in the journ­al Pub­lic Opin­ion Quarterly is per­haps the largest study on the primacy ef­fect to date, ana­lyz­ing all statewide Cali­for­nia elec­tions between 1976 and 2006. Cali­for­nia ro­tates can­did­ate bal­lot or­der dis­trict by dis­trict. While that ran­dom­iz­a­tion is not of the same rig­or that a lab study would em­ploy, it’s as good of a nat­ur­al ex­per­i­ment as the re­search­ers can ana­lyze.

The ana­lys­is found when can­did­ates were lis­ted first (no mat­ter the bal­lot type), “on av­er­age, across all con­tests, can­did­ates re­ceived nearly half a per­cent­age point of ad­di­tion­al votes com­pared to when they were lis­ted either in the av­er­age of all later po­s­i­tions.”

Fur­ther­more, “82 per­cent of all can­did­ates per­formed bet­ter when lis­ted first than when lis­ted later.”

“Sim­u­la­tions sug­gest 9 per­cent of the races could have been dif­fer­ent due to the primacy ef­fect if one par­tic­u­lar name or­der had been used throughout the state in­stead of ro­tat­ing,” the study’s con­clu­sion reads.

Con­sid­er­ing this data, and as­sum­ing what’s true of voters in Cali­for­nia is true across the coun­try, it’s not an over­state­ment to say the fate of Amer­ica has been forever changed be­cause of this ef­fect. In 2000, in Flor­ida, George W. Bush won by less than 1 per­cent­age point. And every bal­lot in Flor­ida lis­ted Bush first.

“If Flor­ida had done what Cali­for­nia or Ohio do, by ro­tat­ing name or­der, we have very strong evid­ence to sug­gest, that most likely, Al Gore would have been elec­ted pres­id­ent,” Jon Kros­nick, a study coau­thor (and jazz drum­mer) tells me. “That’s a pretty power­ful im­plic­a­tion that as we head up to the 2014 and 2016 elec­tions — that there’s something broke about this sys­tem.”


“It would be really un­for­tu­nate if some­body learned about this lit­er­at­ure and said, ‘Oh boy, voters are idi­ots.’ “

So is hand dom­in­ance a strong enough factor to in­flu­ence a pres­id­en­tial race? Could a tar­geted lefty get-out-the-vote cam­paign tip a vot­ing pre­cinct one way or the oth­er?

Let’s break down the res­ults of the Polit­ic­al Psy­cho­logy pa­per. Righties showed a bi­as for the can­did­ate on the left be­cause it is the first name they read. That’s con­sist­ent with oth­er re­search on primacy, that there’s a bi­as for the first in a list. Lefties showed that ef­fect, as well as an ad­di­tion­al left-hand bi­as: Lefties chose the can­did­ate on the left be­cause his was the first name they read and be­cause they have a pos­it­ive as­so­ci­ation with things on the left. Where­as among righties, the can­did­ate on the left showed a 21 per­cent ad­vant­age, among lefties, that jumped up to a 36 per­cent ad­vant­age.

There’s a huge caveat here. These res­ults were pulled from an ex­per­i­ment on a fic­ti­tious elec­tion. And they are the first of their kind — it takes years of re­pet­it­ive res­ults to nail down a phe­nomen­on. So take cau­tion in ex­tra­pol­a­tion. “I don’t ex­pect that we would see any­thing like that enorm­ous, ri­dicu­lous, per­cent­age point dif­fer­ence in real elec­tions,” Cas­as­anto says of the 21 per­cent and 36 per­cent ad­vant­ages. “But in light of Jon [Kros­nick]’s pre­vi­ous data. I think we have every reas­on to be­lieve that these ef­fects are and can be found in real elec­tions.”

Aside from the in­flu­ence of hand dom­in­ance, Cas­as­anto and his col­leagues (Kros­nick was also a coau­thor on the Polit­ic­al Psy­cho­logy pa­per) found the primacy ef­fect was most prom­in­ent among people provided with the least inform­a­tion about the can­did­ates, those who were most am­bi­val­ent about the can­did­ates, those who had lower levels of edu­ca­tion, and those least en­gaged in think­ing about the elec­tion. Curi­ously, there’s a stronger primacy ef­fect for top-tick­et can­did­ates, such as for pres­id­ent or gov­ernor, than for down-tick­et can­did­ates. Kros­nick the­or­izes this is true be­cause people feel more of an ob­lig­a­tion to vote in these con­tests, even when they don’t have a clear opin­ion.

But as com­plic­ated as pars­ing down why people be­have like this is, the solu­tion to mit­ig­ate the bi­as is su­premely simple: ran­dom­ize the bal­lot or­der dis­trict-by-dis­trict, like Cali­for­nia does, and present the names ver­tic­ally to dis­count the left-hand bi­as. Though some states do ro­tate bal­lot or­der, Cas­as­anto and his col­leagues find most do not have such safe­guards.


The ques­tion lurk­ing in the back­ground here is this: What does it say about demo­cracy if elec­tions can be thrown by the sub­lim­in­al quirks of the brain?

Bal­lot or­der isn’t the only psy­cho­lo­gic­al factor at play. Con­sider that chil­dren can pre­dict elec­tion out­comes just by choos­ing among can­did­ate head­shots. That’s how power­ful our bi­ases to­ward cer­tain, com­pet­ent-look­ing faces are. Face­book might have in­flu­enced thou­sands of young people to go to the polls in 2012 be­cause the site told users which of their friends voted, in­creas­ing the so­cial pres­sure to do the same.

“It would be really un­for­tu­nate if some­body learned about this lit­er­at­ure and said, ‘Oh boy, voters are idi­ots,’ ” Kros­nick says. After all, it’s just at most a few per­cent of voters who are show­ing these ef­fects. But at the same time, our elec­tions have to re­cog­nize that hu­mans aren’t com­pletely ra­tion­al. And when races be­come so tight, these quirks can­not be dis­coun­ted.

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