Pigs

Pigs are as capable as dogs, and we keep them in crates

By WhyStopHarmingAnimals.com

Pigs are as capable as dogs on many of the tests scientists use to study animal minds[2]. They solve problems on their own[3], learn what a mirror shows[6], and can steer a cursor on a screen[5]. About 1.5 billion pigs were slaughtered in 2024, roughly 4.1 million every day, which makes them the most killed mammal raised primarily as a farm animal. Most of them never see the sun.

As smart as dogs

In 2015, Marino and Colvin reviewed the research on pig cognition for the International Journal of Comparative Psychology[2]. They rejected the idea that pigs are "significantly less intelligent than dogs[2]." Memory, telling objects apart, complex social lives and individual personalities are all well documented in pigs[2], and the two species share a long list of cognitive abilities[2].

Direct comparisons bear this out[3][4]. In a 2020 study in Animal Cognition, pigs and dogs were given an "impossible task," a box they could not open[3]. Dogs turned to the nearby human sooner and for longer, while pigs kept working at the apparatus[3]. The authors attributed that to differences in how each species is inclined to communicate with people, and found no deficit in pig intelligence[3]. A 2019 study in Frontiers in Psychology found that young pigs and dogs can both learn to follow human pointing cues[4]. Dogs treat people as more important social partners, but both species have the capacity to learn the cue[4].

Pigs playing video games

Croney and Boysen trained four pigs, named Hamlet, Omelette, Ebony and Ivory, to move a cursor on a screen with a joystick to reach targets for food[5]. Their results, published in 2021, showed all four scoring significantly above chance on their first attempts at the hardest, one-walled targets[5].

They managed this with eyes on the sides of their heads and no hands, working the joystick with their snouts[5]. What limited them was the equipment. Four animals is a small sample, and the study shows what pigs can learn rather than an average across the species.

Pigs understand mirrors

In a 2009 study in Animal Behaviour, Broom and colleagues gave young pigs five hours of experience with a mirror[6]. Then they hid a food bowl that could only be seen in the reflection[6]. Seven of the eight pigs found it, walking around a barrier to the real location in an average of 23 seconds[6]. Pigs with no mirror experience looked behind the mirror instead[6]. The researchers ruled out smell and location biases[6].

To find the bowl, a pig has to understand that the image in the glass stands for something elsewhere in the room. That is a mental representation of the world, and pigs pick it up within hours.

What a crate takes away

Given enough space, pigs keep separate areas for sleeping and for dunging. They are clean animals when they are allowed to be. They also show emotional contagion, picking up the fear or the calm of the pigs around them, which only matters to an animal with a social life to lose.

Gestation crates are built to make that life impossible. A pig confined in one cannot keep a clean place to sleep apart from where she dungs, and cannot live alongside other pigs. The system treats an animal who can learn a joystick[5] and read a mirror[6] as a unit of production.

We do not have to keep pigs that way, and we do not have to raise them for food at all.