Cannibalism, slavery, wearing human skin, corpses: most pawns have a severe distaste for these things. If you let them happen in your colony it will impart significant mood penalties on many colonists.
In dire circumstances it can be necessary to use every resource, even the human ones. A number of traits can make this feasible as a core strategy for a colony. Some might even make it the preferable way.
The three traits below make a colonist react indifferently or even enthusiastic towards human abuse. If there is more than one of the traits on the same person, the most beneficial one applies (e.g. a Cannibal will always receive +20 mood per day by eating raw human flesh, no matter what other traits that colonist has). Any of the traits remove the penalty from butchering humans.
Has no issues seeing corpses or butchering them but still suffers penalties from eating human flesh or wearing human skin clothing. Has no qualms about slavery and organ harvesting.
The only one who doesn't mind seeing rotting corpses; likes to wear human skin. Does not like cannibalism or slavery. Does not mind wearing tainted apparel (ie. taken from a dead body).
Loves to eat human flesh and also likes clothing made from skin. Does not like slavery or organ harvesting.
Table of mood effects
|Trait||Observes corpse||Observes rotting corpse||Butchers human||Somebody butchers human (colonywide)||Eats raw human flesh||Eats meal with human flesh||Wears human skin clothing||Trades human flesh or leather||A slave is sold (colonywide)||An organ is harvested (colonywide)|
|None||-3 Mood (0.25 days. 3 Stacks. 0.5 Stack Multiplier)||-7 Mood (0.25 days. 5 Stacks. 0.3 Stack Multiplier)||-6 Mood (6 days. 4 Stacks. 0.75 Stack Multiplier)||-6 Mood (6 days. 1 Stack)||-25 Mood (1 day. 3 Stacks. 0.25 Stack Multiplier)||-20 Mood (1 day. 3 Stacks. 0.25 Stack Multiplier||-3/-5/-7/-8 Mood||No Debuff||-5 Mood (3 days. 5 Stacks)||-5 Mood (7.5 days. 5 Stacks. 0.75 Stack Multiplier)|
|Psychopath||Immune to Debuff||Normal Penalty||Immune to Debuff||Immune to Debuff||Normal Penalty||Normal Penalty||Normal Penalty||No Debuff||Immune to Debuff||Immune to Debuff|
|Bloodlust||Immune to Debuff||Immune to Debuff||Immune to Debuff||Immune to Debuff||Normal Penalty||Normal Penalty||+3/+5/+7/+8 Mood||No Debuff||Normal Penalty||Immune to Debuff|
|Cannibal||Immune to Debuff||Normal Penalty||Immune to Debuff||Immune to Debuff||+20 Mood (1 day. 1 Stack)||+15 Mood (2 day. 1 Stack)||+3/+5/+7/+8 Mood||No Debuff||Normal Penalty||Normal Penalty|
It is possible to butcher human corpses without penalty for anyone if you send everybody who would be debuffed off the map (on a caravan) until all humans have been chopped up. You need a butcher who can butcher humanlikes without debuff (or else your butcher will take a severe mood penalty).
Colonists who are not on the map when a humanoid corpse is butchered do not receive the mood penalty "We butchered humanlike". It is sufficient to put all colonists who are neither Psychopath, Bloodlusted nor Cannibal on a temporary caravan (take no items), send them off the map to an adjacent tile and make the caravan rest immediately. Then have your psycho butchers chop up all the humans. Re-enter with the caravan when it is done. It is not necessary to take any prisoners off the map, as they do not receive the debuff in any case.
Alternatively, given the mood penalty is releatively low for human butchery, only -6, the penalty can just be taken. Some additional care cam be to maintain mood levels through other means to make this more palatable, this includes providing additional recreation, psychic soothe pulsers, better meals, drugs or improved bed and rec rooms. Just providing 1 lavish meal per affected colonist per day for the 10 day duration is more then enough to counter the penatly. It is recommended to use a non-affected pawn to actually do the butchery though, as the penalties stack and -12 is a significant debuf. Also keep in mind that the butchering pawn's social standing will be much reduced in the eyes of affected pawns. This can ruin relationships by causing a pawn to hate their spouse for example.
That said, doing this can be quite profitable especially on higher difficulties where you get raided a lot.
The caravan move does not work for organ harvesting or slavery; these transgressions are detected by colonists anywhere on the map, however countering the debuff with other buffs is still a viable method.
Everybody will handle human meat without complaint, as long as they do not have to eat it in any form.
Storing human corpses for butchery will result in the Observed Corpse mood debuf, this can be prevented by hiding the corpses in shelves. See that page for details.
Human leather fetches a good price. It can also be used for furniture without penalty. Human meat can be sold, fed to carnivores, turned into kibble, or converted into Chemfuel at the Biofuel refinery.