Take our obsession with eating and the festivity associated with it, as compared to our shame and secrecy about how we eliminate the waste from it.
Flip the switch and we suddenly go off and eat in private and don’t speak of it, while making elaborate plans and guest lists and all sorts of decorations and hoopla over the other function.
What are some other switches we could flip?
What if we mourned when someone was born and threw huge parties to celebrate their deaths?
Celebrating old age, unattractiveness and obesity, instead of youth, beauty and being slim?
So that all the anti-wrinkle products were actually pro-wrinkle, and it was cool to look old. Instead of paying for liposuction, people would pay for a surgery that makes them overweight.
that’d be weird.
I wouldn’t mind a switch that made us think that raw broccoli, tofu, and bean sprouts taste like candy, cake, & ice cream & vice versa.
I would like to buy this switch! 
I’ve often thought that it would be a fascinating story to explore what would happen if we all woke up empathic one day. No more being able to tell yourself rationalizing stories about what you’re doing to other people - you’d FEEL it.
I’d love it if we could stop convincing ourself that being violently cruel to other people (or things) was entirely justified by our own emotions.
You’re not Irish, I take it?
I would like to see a switch that would eliminate magical thinking. No more hooking the emotions in and believing something in spite of evidence to the contrary. If there’s no evidence of something one way or the other, no problem; but if there is evidence, we’d be incapable of going “la la la la I can’t hear you”.
Let this effect cut in at puberty.
Very quickly, one person would go mad from it. Then the madness would spread.
We could flip a switch to make all straight people gay and all gay people straight.
I wonder how the straight minority would feel then.
Reminds me of a bit from a Spider Robinson speech he gave at a sci-fi convention
Imagine a world not afraid of sex.
I have nothing against violence in entertainment, but I’m not interested in dismemberment and torture porn and sharp things getting where they shouldn’t. But I remember seeing ‘Irreversible’ and being surprised that so many were amazed by the beating-down but repulsed by the rape scene. I’m the opposite. A guy gets famous doing harm to himself, but the merest flash of nudity on tv and six-figure fines are levied. It’s sort of crazy.
Most of humanity is unwilling to have sex with me…
Can you imagine the chaos if most of humanity tried to have sex with you? The crowding alone–
Philip K. Dick’s Counter-Clock World imagined a world where time shifted so that people now lived backward. The dead woke up in graves, and lived getting younger until it became necessary to find a womb to climb into. Excrement, under a euphemism, was introduced into one’s nether orifices socially, via tube, while disgorgement of food via one’s mouth was considered shameful and done in private.
How about for sex to be incredibly unpleasant, but pregnancy and childbirth intensely pleasurable (bit of a bum deal for the men, that one)
What if we were nocturnal?
There are certainly some people who would be, if they could get good jobs at night.
Sort of similar- I fantasize that for one day humanity is completely objective. It won’t do anything for people who have a systematic philosophy of evil, but I think it would work for ordinary shmoes. You’ve got a guy who grew up in a racist community, and this one black guy shortchanged him twenty years ago, and so obviously black people are insert-insult-here. But today he wakes up and knows he’s just using a couple of selective incidents to confirm a baseless world view. He can’t even come up with a new reason, or deny that he’s been a jerk.
Then the next day the switch is flipped back off. Because otherwise people would go crazy.
That there was an omniscient all powerful invisible being that created the universe and controlled our lives, was vengeful and wrathful, but granted you requests if you asked really really hard. And that there were a number of people who were aware of this being’s existence but were shunned by greater society for expressing this truth. Only those who were rational and professed complete individual existential autonomy were allowed to be chosen as leaders.
When I first started reading your OP, I thought you were going to say what if we switched our obsession with eating and the festivity associated with it with our privacy and secrecy about sex?
We suddenly go off and eat in private and don’t speak of it, while making elaborate plans and guest lists and all sorts of decorations and hoopla over the other function. Now that might be fun!