This chapter argues that the wellspring of theatre can be found in childhood pretend play – a universal human phenomenon that leaves us all capable of theatrical behavior, whether as performers who enact make-believe “realities” or as audience members who imaginatively engage in others’ make-believe. Such play is likely associated with an evolutionary adaptation for advanced symbolic thinking. Theatre might be a by-product of pretend play, carried over into adult life, but it might be an exaptation in which childhood pretend play has been co-opted for the new evolutionary purpose of allowing performers and audiences to explore “what-if” situations in ways that compel attention through the performers’ presence and artistry, and the empathy given to their enacted characters by the audience. The universality of pretend play suggests this behavioral trait evolved more than 50,000 years ago, at which point humans had begun their globalizing expansion from Africa.

The USA has among the highest levels of mental illness of all countries, together with the most treatment. We seek happiness through mechanisms that produce pleasure, most of which are not effective. Those lower down in the hierarchy use more destructive means to gain gratification, thereby becoming worse off. Americans may suffer more pain than people in other rich nations, especially social pain in response to chronic stressors present here. We consume 80% of the world’s opioids Smartphone use, especially among youth, may be harmful for mental health. Evolutionary pressures make us live to reproduce and nurture the progeny until they can have children. Various mental illnesses that don’t impact propagation can manifest, especially in later life, such as anxiety to cope with danger. Mental health is political, like other aspects of health

This chapter introduces the central ideas in Darwin’s Expression, poses the main interpretive questions that scholars have raised, and outlines my answers to those questions. Why does Darwin analyze expressions in terms of heritable habits, recalling Lamarck’s debunked theory of evolution, when his own theory of natural selection provides a superior alternative? My answer is that Darwin embraces Hartley’s associationist theory of mind, which posits habit as the basis of thought. I claim that multiple puzzling features of Expression are resolved once we view Darwin as an associationist philosopher.

This chapter argues that Darwin’s philosophical theory of emotion has been forgotten due to paradigm shifts in biology, psychology, and philosophy. These shifts have caused researchers to neglect associationist theories of emotions, including Darwin’s contributions to this school of thought. Having explained why Darwin’s philosophy was forgotten, I conclude by explaining why it should be remembered, given its relevance for contemporary emotions research.

This chapter examines Darwin’s analysis of emotional expression. It is widely accepted that Darwin wrote Expression to refute Sir Charles Bell’s theory that God created humans with special muscles to express their emotions. However, scholars have overlooked the fact that Bell developed his theory to refute Erasmus Darwin’s associationist analysis of emotional expression, inspired by David Hartley, and that Charles Darwin defends his grandfather’s analysis against Bell’s objections. I demonstrate that Charles’s defense of Erasmus’s associationist theory, which denies that expressions occur for the sake of communicating emotions, explains Charles’s puzzling reluctance to claim that expressions evolved to serve as signals in communication.

Ch. 6 New developments in science and philosophy can led to a new natural theology based on induction and probability. Natural theology today requires insights from the sciences, analytic philosophy, and hermeneutics.

Long assumed to have no real function, we now understand the importance of the prefrontal cortex for a wide range of cognitive functions, including decision-making. Some of the earliest understanding of the role of the prefrontal cortex came from the famous case study of Phineas Gage. Through a mining accident, Gage’s prefrontal cortex was extensively damaged. He showed no observable impairments in motor, sensory or memory skills. He however did show marked differences in personality and planning. Over the following decades, research built upon understanding of the role of the prefrontal cortex. Today, the prefrontal cortex as a region is recognised across many species and is considered the most evolutionarily advanced in humans. The current consensus is that prefrontal cortex is an integration area, integrating information from all over the brain.

Chapter 3 picks up on the topic of cheating and the benefits this adaptation confers to those who are able to pillage others’ resources undetected. It looks at the evolutionary implications of this capability in the human species, which can be traced back to the development of Theory of Mind. It then proceeds to consider cognitive adaptations that characterise mental life in the human species, marked by biases and heuristics that confer evolutionary advantages in terms of efficiency in the cognitive processing of salient information. These include stereotyping and xenophobia, which enabled our ancestors to distinguish friend from foe and to limit collaboration with similarly interested others for mutual benefit.

This chapter explores the phenomenon of embodiment, or how bodies vary because of their embeddedness in different cultural, social, and material landscapes. Understanding embodiment entails studying the influences of the social–cultural world on bodies, and the influences of biological processes on social, semiotic, and experiential worlds. Drawing on anthropological, feminist, and disability studies scholarship, and those in contemporary biological sciences, we offer some tools for thinking about how bodily states and processes are affected by their perception, representation, and treatment within people’s lived worlds, and vice versa. A processual, “bio-looping” model helps to explain how transformations of body and world in complex embodiment might work. Emerging empirical work in the biological sciences provides evidence for the deep entanglements of social and biological systems. The intersections among meaning and perception (“interoceptive affordances”) highlight how meaning shapes perception of bodily processes and sensations. Canna’s study of demonic possession illustrates how interoceptive affordances contribute to embodied experiences and ways of being in the world.

Outside of our fellow mammals, our next closest relatives are reptiles. As both birds and mammals are warm blooded (endothermic) and have four-chambered hearts, one might be tempted to think that the sister group to mammals would be birds. But the story is much more complicated than that, especially because birds are actually reptiles.

Reptiles include four main lineages: (1) turtles, (2) lizards and snakes, (3) crocodilians, and (4) dinosaurs, including birds. Indeed, birds are reptiles – birds are a surviving lineage descended from bipedal predatory dinosaurs! In decades past, there were five “classes” of vertebrates (animal groups with backbones): fishes, amphibians, mammals, reptiles, and birds. In fact, many basic treatments still list these groups. For example, Encyclopedia Britannica still has an article entitled: “Five Vertebrate Groups.” But there are major problems with two of these old groups: neither fishes nor scaly reptiles are monophyletic.

I have argued that one of the major misconceptions about evolution and the tree of life is that some species or lineages are considered more “primitive” than others – this chapter will delve more deeply into this misconception and one of its key causes. Across the tree of life, certain lineages – including the platypus, lungfishes, and mosses – are frequently labeled as more primitive than other members of their groups. Mammals provide several good case studies demonstrating the reasons for this longstanding misperception. Researchers, journalists, and filmmakers all seem obsessed with discussing certain lineages that somehow seem primitive to them. This misconception about primitive lineages is problematic for two major reasons. First, it leads to a general misunderstanding of evolution, which can lead to fundamental misunderstandings across all of biology, including human health.

Fossils provide a unique window into how evolution has unfolded. In particular, transitions in the fossil record provide compelling evidence for how major evolutionary changes have happened. One of the most well-known transitions is from fish-like vertebrates to the first land vertebrates – our earliest tetrapod ancestors. (The word tetrapod refers to the groups of vertebrates with four legs, namely mammals, reptiles, and amphibians.) Paleontologists had known that transitional fossils connecting aquatic and terrestrial vertebrates must exist. There were abundant fossils of vertebrates with fins from around 400 mya, and there were abundant fossils of terrestrial tetrapods with limbs from around 350 mya. But key fossils were missing – those that could show details of how the evolutionary crawl onto land had occurred.