Scientists Identify the Evolutionary “Purpose” of Consciousness

Summary: Researchers at Ruhr University Bochum explore why consciousness evolved and why different species developed it in distinct ways. By comparing humans with birds, they show that complex awareness may arise through different neural architectures yet serve similar purposes.

New research examines why consciousness evolved by comparing humans with birds.

What evolutionary purpose does consciousness serve, and what insights can birds offer about its origins? These questions are at the heart of two new studies from researchers at Ruhr University Bochum.

Over the past twenty years, interest in the science of consciousness has grown rapidly, yet a key issue remains unresolved: What is consciousness actually for? Why did it appear in the first place? Finding answers is essential for understanding why certain species (such as our own) developed conscious awareness, while others (such as oak trees) did not. Research on bird brains adds another important perspective, showing that evolution can produce similar functional outcomes for consciousness even when the underlying brain structures differ. The teams led by Professors Albert Newen and Onur Güntürkün at Ruhr University Bochum, Germany recently published their findings in the journal Philosophical Transactions of the Royal Society B.

Purposes of pleasure and pain?

Our conscious experience shapes every part of our lives through moments of enjoyment as well as discomfort. We might notice the warmth of sunlight on our skin or listen to birdsong and feel a sense of ease.

At other times, we become aware of pain, such as a knee that aches after a fall, or we struggle with persistent feelings of pessimism. This raises a fundamental question: why would living beings evolve a capacity that includes both pleasurable sensations and experiences that can be deeply unpleasant or even overwhelming?

Albert Newen and Carlos Montemayor describe consciousness as consisting of three forms, each serving a distinct purpose: 1. basic arousal, 2. general alertness, and 3. reflexive (self-)consciousness.

Stage One: Basic Arousal

"Evolutionarily, basic arousal developed first, with the base function of putting the body in a state of ALARM in life-threatening situations so that the organism can stay alive," explains Newen. "Pain is an extremely efficient means for perceiving damage to the body and to indicate the associated threat to its continued life. This often triggers a survival response, such as fleeing or freezing."

Stage Two: General Alertness

A second step in evolution is the development of general alertness. This allows us to focus on one item in a simultaneous flow of different information. When we see smoke while someone is speaking to us, we can only focus on the smoke and search for its source.

"This makes it possible to learn about new correlations: first the simple, causal correlation that smoke comes from fire and shows where a fire is located. But targeted alertness also lets us identify complex, scientific correlations," says Carlos Montemayor.

Stage Three: Reflexive (Self-)Consciousness

Humans and some animals then develop a reflexive (self-)consciousness. In its complex form, it means that we are able to reflect on ourselves as well as our past and future. We can form an image of ourselves and incorporate it into our actions and plans.

"Reflexive consciousness, in its simple forms, developed parallel to the two basic forms of consciousness," explains Newen. "In such cases, conscious experience focuses not on perceiving the environment, but rather on the conscious registration of aspects of oneself."

This includes the state of one's own body, as well as one's perception, sensations, thoughts, and actions. To use one simple example, recognizing oneself in the mirror is a form of reflexive consciousness. Children develop this skill at 18 months, and some animals have been shown to do this as well, such as chimpanzees, dolphins, and magpies. Reflexive conscious experiences – as its core function – makes it possible for us to better integrate into society and coordinate with others.

What Birds Perceive

Gianmarco Maldarelli and Onur Güntürkün show in their article that birds may possess fundamental forms of conscious perception. The researchers highlight three central areas in which birds show remarkable parallels to conscious experience in mammals: sensory consciousness, neurobiological foundations, and accounts of self-consciousness.

Firstly, studies of sensory consciousness indicate that birds not only automatically process stimuli, but subjectively experience them. When pigeons are presented with ambiguous visual stimuli, they shift between various interpretations, similar to humans. Crows have also been shown to possess nerve signals that do not reflect the physical presence of a stimulus, but rather the animal's subjective perception. When a crow sometimes consciously perceives a stimulus and does not at other times, certain nerve cells react precisely according to this internal experience.

Secondly, birds' brains contain functional structures that meet the theoretical requirements of conscious processing, despite their different brain structure. "The avian equivalent to the prefrontal cortex, the NCL, is immensely connected and allows the brain to integrate and flexibly process information," says Güntürkün. "The connectome of the avian forebrain, which presents the entirety of the flows of information between the regions of the brain, shares many similarities with mammals. Birds thus meet many criteria of established theories of consciousness, such as the Global Neuronal Workspace theory."

Thirdly, more recent experiments show that birds may have different types of self-perception. Even though some species of corvids pass the traditional mirror test, other ecologically significant versions of the tests have shown further types of self-consciousness in other bird species. "Experiments indicate that pigeons and chickens differentiate between their reflection in a mirror and a real fellow member of their species, and react to these according to context. This is a sign of situational, basic self-consciousness," says Güntürkün.
The findings suggest that consciousness is an older and more widespread evolutionary phenomenon than had previously been assumed. Birds demonstrate that conscious processing is also possible without a cerebral cortex and that different brain structures can achieve similar functional solutions.

References: "Three types of phenomenal consciousness and their functional roles: unfolding the ALARM theory of consciousness" by Albert Newen and Carlos Montemayor, 12 November 2025, Philosophical Transactions B.
DOI: 10.1098/rstb.2024.0314

"Conscious birds" by Gianmarco Maldarelli and Onur Güntürkün, 12 November 2025, Philosophical Transactions B.
DOI: 10.1098/rstb.2024.0308