Pigs

Cognitive abilities:

Problem-solving:

• Can learn to operate joystick-controlled video games

• Navigate complex mazes

• Use mirrors to locate hidden food (mirror-mediated spatial awareness (using mirror reflections to locate hidden food — Broom et al., 2009, though a replication attempt by Gieling et al., 2014 found weaker results))

• Learn from watching other pigs

Memory and learning:

• Excellent long-term memory

• Can remember locations of food sources

• Recognize individual humans and pigs

• Learn names and respond to them

Social intelligence:

• Complex social hierarchies

• Can manipulate and deceive other pigs

• Form lasting friendships

• Show empathy toward distressed companions

Emotional capacity:

Research demonstrates pigs experience:

• Joy (play behavior, vocalizations)

• Fear and anxiety

• Anticipation of positive and negative events

• Depression in barren environments

• Grief and mourning

Comparison to other animals:

While popular comparisons to human children are oversimplified, pigs have demonstrated:

• Comparable performance to dogs on spatial learning and object discrimination tasks

• Comparable performance to some primates in certain problem-solving contexts

• Capacities that indicate complex cognitive processing, though cross-species comparisons on a single "intelligence" scale are scientifically problematic

Scientific recognition:

The Cambridge Declaration on Consciousness was proclaimed at the 2012 Francis Crick Memorial Conference. More recently, the New York Declaration on Animal Consciousness (2024), led by Andrews, Birch, and Sebo at NYU, was initially signed by 40+ leading researchers in consciousness, neuroscience, and animal cognition — including Christof Koch, Anil Seth, David Chalmers, and Irene Pepperberg — representing a broader and more recent scientific statement on the realistic possibility of consciousness across a wide range of animals including mammals, birds, reptiles, fish, cephalopods, and insects recognized that pigs, along with other mammals and birds, possess the neurological substrates for conscious experience.

Implications for welfare:

• Boredom from lack of stimulation

• Frustration from inability to express natural behaviors

• Social stress from overcrowding

• Psychological trauma from separation

Evidence quality: Broom (2010) reviewed cognitive ability and awareness in domestic animals and their relevance to decisions about obligations to animals; the section also cites Marino & Colvin (2015), Held et al. (2001), and the Cambridge Declaration on Consciousness (2012).