We argue that Kline's analysis does not account for the evolutionary mechanisms that can explain the uniqueness of human teaching. We suggest that data should be complemented by an analysis of archaeological material with respect to what forms of teaching are required for the transmission of technologies over generations.

We welcome Kline's systematic overview of teaching from a functional evolutionary perspective. However, Kline's framework does not provide satisfying characterization of the adaptive problems driving the evolution of teaching through communication found in humans, where the key function is better characterized in terms of licensing inferences to opaque generic content than in terms of overcoming shortages of access and attention.

One of the challenges to a unifying framework for the study of teaching behavior will be to distinguish, if possible, between teaching by evaluative feedback and punishment.

Kline argues that it is crucial to isolate the respective roles of teaching and learning in order to understand how pedagogy has evolved. We argue that doing so requires testing species that learn from pedagogy but that rarely teach themselves. Here, we review how one previously neglected species – domesticated dogs (Canis familiaris) – may allow researchers to do just that.

Parenting, conceptualized as a specific form of teaching, may inform mentalistic, culture-based, and functional definitions. Combined brain-imaging, hormone-measurement, and cognitive-behavioral analyses indicate the importance of mentalization circuits. These circuits appear to function according to culture, and cross animal species. Further, these approaches shed light on sex differences through work on fathers as well as mothers, are affected by psychopathology, and may be amenable to treatment in ways that may be applied to optimize teaching.

A unified account of teaching such as Kline's can and should accommodate facts about teaching in nonhuman animals and culturally diverse populations. But to benefit from Kline's insights, we need to understand how her taxonomy of teaching maps onto a taxonomy of learning. The crux of the problem for scientists studying humans and nonhumans is to determine not only how different models teach, but how individuals select models, and how they learn differently from different models.

Kline's evolutionary analysis of teaching provides welcome reframing for cross-species comparisons. However, theory based on competition cannot explain the transmission of human cultural elements that were collectively created. Humans evolved in a cultural niche and teaching-learning coevolved to transmit culture. To study human cultural variation in teaching, we need a more articulated theory of this distinctively human engagement.

Direct active teaching by parents is largely absent in children's lives until the rise of WEIRD (Western, educated, industrialized rich, democratic) society. However, as mothers become schooled and missionized – like Kline's Fijian subjects – they adopt “modern” parenting practices, including teaching. There is great variability, even within WEIRD society, of parental teaching, suggesting that teaching itself must be culturally transmitted.

In Kline's target article, the role of motor behavior in teaching is missing. However, it is so important that we cannot avoid taking into account the movements of another person when performing our own movements. Moreover, the state of mind is embodied. Consequently, teaching should integrate the role of motor behavior to enhance teacher/learner social interactions.

Kline's functional categories for the evolution of teaching blur some valuable distinctions. Moreover, her account provides no answer to the question of why direct active teaching seems to be a uniquely human phenomenon.

Kline proposes an evolutionary framework for teaching as a major base of human culture, in which she outlines how different types of teaching may solve adaptive problems with a focus on human behavior. Here it is argued that the ability to teach and the different types of teaching behavior may not only solve adaptive problems, but also create them.

Kline presents an excellent synthesis of teaching theory and research, with cogent arguments regarding its prevalence. In this, she claims that “active teaching” is human specific, and presents tangible reasons why. But in doing so, she overlooks a critical aspect of the human condition that may have arisen only recently in our evolutionary history: Childhood as a life stage.

The synthesis provided by Kline in the target article is noteworthy, but ignores the inseparable role of play in the evolution of learning and teaching in both humans and other animals. Play is distinguished and advantaged by its positive feedback reinforcement through pleasure. Play, especially between adults and infants, is probably the platform from which human learning and teaching evolved.

In line with Kline's taxonomy, highlighting teaching as an array of behaviors with different cognitive underpinnings, we advocate the expansion of a specific line of research on mind, brain, and teaching. This research program is devoted to the understanding of the neurocognitive mechanisms and the evolutionary determinants of teaching skills, with the ultimate goal of helping teachers improve teaching quality.

An evolutionary framework on human teaching is not well equipped to explain the nature of human teaching unless it specifies the subserving cognitive and motivational mechanisms. Only a theory that speculates on the psychological processes provides testable predictions and stimulates further empirical research.

Human civilization has a system of different social tools, institutions, and types of positive and negative work with teaching/learning determined by different interests of many actors. Negative work is more hidden and less studied. A paradoxical adaptive problem for teachers with good intentions is design of teaching/learning that equips pupils for learning in future environments unknown to the teachers.

Kline succeeds in demonstrating the value of an approach that integrates information from various scientific and social disciplines, but her framework does not uniformly provide clarity. Specifically, inclusion of situations in which knowledgeable individuals do not actively donate information is misguided. Passive tolerance by demonstrators should continue to be excluded from definitions of teaching, in order to focus on situations in which selection has favored behaviors that are specifically geared to promoting learning in others.

Arguments about the nature of teaching have depended principally on naturalistic observation and some experimental work. Additional measurement tools, and physiological variations and manipulations can provide insights on the intrinsic structure and state of the participants better than verbal descriptions alone: namely, time-series analysis, and examination of the role of hormones and neuromodulators on the behaviors of teacher and pupil.

We agree with Kline that a lack of unification is preventing progress in understanding the occurrence of teaching behaviour and the selective pressures influencing its presence. However, we feel that the proposed framework, which incorporates mentalistic and cultural approaches, continues to overlook cases of teaching in nonhuman animals. We advocate the comparative functionalist framework to identify the proximate causes of teaching behaviour in both humans and other animals.

Cultural accounts of how people facilitate learning extend beyond the five types of teaching outlined by Kline's target article. Rather than focusing so exclusively on individual teaching, cultural accounts examine the mutually constituting efforts of individuals who are teaching, together with those who are learning. Further, cultural research emphasizes the community contexts of people's arrangements for learning and their teaching/learning interactions.