Homo Habilis is less a species distinction than a taxonomic misstep. Because of the very limited fossil record data from the time of homo habilis, we don’t really know if its one species of many. Most of the work that talks about h habilis draws a closer comparison between habilis and the australopithecines than homo habilis and homo erectus.
The australopithecines were around before homo habilis. the australopithecines may have even been alive at the same time as habilis, but there is a key set of distinctions between the two: Tool use and meat eating. This made habilis stand out. Yes, the australopithecines were bipedal, but other than that, they were probably more like chimps in most ways. They ate leaves, seeds and buried food, which is not what chimps eat, but this diet does not do what meat did, socially. They had a social structure in accordance with their intelligence, and probably followed similar rules to those of chimps and apes.They were sexually dimorphic, although it is debated to what degree, but this does support that they had a social structure much like apes. They had an ape like rib cage, so they were probably still climbing trees.
Homo habilis as a term really refers to early homo. Early homo can be thought of as a group that contains the australopithecines, homo habilis proper, and homo rudolfensis. As a group, they demonstrate the first, and less significant step towards humanity. With second order intentionality, and second order hand-eye coordination, they made themselves stand out just enough to be acknowledged. They were bipedal apes, and being bipedal led to no longer being apes.
The archaeological record of the era of habilis is very minimal and makes it difficult to see what happened when. What we do know is that we have bones of australopithecines, h rudolfensis, and h habilis. The sites of early homo species are littered with rudimentary stone tools and animal bone. The australopithecus sites are not.
Mithen says that the archaeological record exposes a branching off of the evolutionary tree”Moreover we can see our ancestors setting off in two different evolutionary directions.The australopithecines went down a route of ever-increasing robusticity as specialized plant-grinding machines, while early homo took a more cerebral route of increasing its brain size.”(pg 95 Australopithecines became better and better at chewing plants, evidenced by their teeth, and habilis became better and better at tool building, and possibly changed social structure.
Coolidge and Wynn corroborate Mithen’s analysis of the australopithecines as bipedal plant grinding specialists “What kind of diet selected for molars with thick enamel?… hard seeds (imagine eating unpopped popcorn) or buried food”(pg 89). They point out that this species was becoming very skilled at extractive foraging, which does require tracking of several locations and planning to order to visit them.
The cognitive repertoire of early homo was certainly limited. but did this time period mark a distinctly different set of cognitive abilities: yes. Were they significant in comparison to those yet to come? no.
Mithen uses the evidence to spin h habilis as more of a cognitive breakthrough than it is. He concentrates on the stone knapping technique, and the single skull which had potential for a larger broca’s area: “This has been examined by Phillip Tobias, one of the foremost authorities on the evolution of the brain. He is confident that a significant development of the broca’s area can be seen…In contrast no such development of Broca’s areas can be seen in the brains of the australopithecines”(pg 110).He tries to qualify that these people were vocalizing with prelinguistic signals, and that they began to travel in different types of social groups.
Coolidge and Wynn do agree that the stone knapping is beyond the ability of a chimpanzee (kanzi and his sister never really mastered it).”Even these earliest stone tools demonstrate a deftness at knapping that exceed Kanzi’s ability, so it is likely that hominins had started knapping earlier than this”(pg97) but they see this as the improvement of an existing competence, and not the budding of a new competence.
Donald treats them as a middle ground for the first major mental transition. He talks about them very briefly in his chapter on mimetic minds, but points out that they were more likely a form of episodic, with homo erectus being the best candidate for the mimetic mind. He points out how they pose a problem for neat and clean categorization of our ancestors: “If it were not for the existence of the famous( and anomalous) habiline skull 1470, with a cranial capacity approaching 800 cc, it would be easy to dismiss the idea that Homo had appeared so early in the archaeological record”(pg 163) . They most likely had episodic minds, but as apes have episodic minds that are more advanced than those of dogs, the episodic mind of early homo was probably more significantly advanced than an apes, despite not marking a change in what abilities it had.
The literature brings up many issues of debate, and while many of these are still open ended, I think it is possible to get an approximate idea of the cognitive and social life of the early homo lineage. We can get this glimpse by appealing to our ever fruitful “ontogeny imitates phylogeny” principle. Outside of the fossil record, our observations of modern chimps and human babies may give us insight into how the australopithecines and homo habilis thought, and how they lived.
My tentative position will be one of moderation. I think that all of those who have written about this have made a point or observation worth preserving. I would place H habilis as a proto-interpreter. that is, a natural teleologist who may have sometimes had the capability for “two model” teleology. They were in a similar place for most of their other causal understanding mechanisms. They were barely able to imitate novel aspects of a behavior, and their physical understanding of things like rocks and bones was probably still limited, but more versatile than a modern chimps.
This means that there probably was not a significant change in social structure. They still were just starting to get shared attention, and probably gesturing, so these new abilities were probably only being used for the purposes an ape would use them : machiavellian social manipulation.They probably did not understand reciprocal altruism, and still traveled in ape like social groups.
They were probably eating meat as more of a major part of the diet. this was indeed a physical change that would open up the potential for later cognitive changes.
The Early homo group is a problematic one for archaeologists, taxonomists, and cognitive scientists alike. The fossil’s from the time period of early homo are few and far between. They also often raise more questions than they answer.
The early homo archaeological record has been plagued with a lack of information from the fossil record, and confusing data concerning the fossils we have found(Wood 2011). We don’t know when and in what populations the different species were in.
We still have much work to do just to figure out the biological/anatomical details of this species, or set of species. To reconcile the differences between the 1470 and 1813 “groups” we need more fossils that are definitively from one group or the other (Lieberman 1996).
Many people also try to fit h habilis and h rudolfensis into the greater picture of the australopithecines of the time.(Anton 2012). The problem With these approaches is that even good anatomical biological information will not tell us about the minds of these people without the use of speculative analysis.
The problems are manifold and the taxonomic issues make it harder for those trying to put the pieces together to get their footing. In The species homo habilis: example of a premature discovery Phillip Tobias illustrates these concerns, with a forward thinking attitude in the direction of moving forward now, knowing that these problems happen(Tobias 1992). These petty taxonomical arguments slow down the research and speculation needed to understand this issue. In the case of h habilis and how we identify it, I think it is safe to say that if we approach it like a group that has commonalities, we can get an approximation of what their mental and social lives may have been like.
The cognitive abilities of homo habilis can be analyzed on two fronts : the limited fossil data/ the genetic distinction of the homo lineage, and speculative analysis of this evidence.
Tobias also contributed to the distinction being concreted (Tobias 2004). He assessed that the brains of the habilis fossils showed “moderate cerebral heightening” and that the increased size of frontal and parieto-occipital lobes was a sign of the homo lineage. If it was contested why before, now at least we have a concrete, physical reason to call homo habilis homo.
This is corroborated by Susan Anton (Anton 2012). Her findings confirm that there was at least one member of the homo lineage around before around 2 million years ago, much earlier than erectus. These early homo had an observable difference in brain size, again according to fossilized skulls.
Genetic testing evidence from the early homo fossils has also backed up these claims(Wood 2011). These genetic markers show that the common ancestor of all humanity had homo habilis as his ancestor.
In Prehistory of the mind, Mithen talks about Daniel Dennet’s intentional systems theory. In The Intentional Stance in Theory and Practice Dennet brings up the idea of orders of intentionality. If an propositional statement is an arrow, then orders of intentionality is how many arrows are needed to map a complex statement or situation. Dennet figures that humans have at most 5 or 6 orders of intentionality ( At the most I can only think about what you might believe I think you believe i think. After that, it gets very confusing). Mithen hypothesizes that maybe early hominin had 3 or four orders of intentionality( pg 108). He also states that chimps only have 2. I would argue that chimps only have 2 under very specific circumstances(Hare 2001).
In the spectrum of teleology, I think the best way of thinking about early hominin is of the 2 level teleologist. This is the stage infants are in after they surpass apes in theory of mind tests. At 14 months, they understand mimicking of basic, but novel behaviors(Meltzoff 1988, Schwier 2006). They are also past apes in basic recognition of reciprocal altruism, and understanding gestures such as pointing (Wrneken 2006, Tomasello 2006).
The 2 level teleologist is still a teleologist. early hominin were not representing each others mental states, but given how close chimps could get in a lab (Hare 2001), they may have known better how to utilize what a conspecific had witnessed or not witnessed. Their intuitive physics was of a second order as well. They understood how to pick up and improve their skill at knapping, which took precise coordination, and conceptualization of how to orient the rock, but there is no evidence that they used these tools to make other tools, such as fastening one to a stick to make a hammer. This was a species that was just starting to get the second level or representation. They could entertain a second representational model of the world, but probably strained to use that model for pretend. If they were applying it to other people, it was probably in regard to goal, and in a purely informational sense (“what did this conspecific witness? ”not “What do they know?”).
These cognitive changes, no matter how slight, probably did change the social lives of early homo. As second order teleologists, they most likely could keep track of more social interactions, and the skill of social manipulation was further advanced, and primed for the later cognitive differences. These cognitive changes around Homo erectus and later were only possible because of these physical changes during the time of early homo.
The physical changes to early homo may be more worth noting than the cognitive ones. The relative sizes of their limbs can tell us more about them than just bipedalism (Haeusler 2004). We know that bipedalism made the birth canal smaller, which led to increased selection for prematurely born babies. This is what allowed for later cognitive changes. babies that needed constant care became more socially intelligent later in life and increased competition for skills such as face recognition, gaze tracking, and strategical planning. We also see that they were at least somewhat sexually dimorphic, which suggests a social life much like apes.
They may have also been eating a lot more meat. this would have led to the shortening of the gut (Anton 2012) this opened up caloric energy for another expensive organ: the brain. This may have not been a cognitive development, but paired with the narrowing of the birth canal, shortening of the gut allowed for the major cognitive and social changes of interpretation, and 4th and 5 order intentionality to come about
When it comes down to it, the physical differences between early homo and chimps are more noteworthy than the cognitive changes. Yes, they would have been able to trick and deceive the modern chimp with relative ease, but they still did not have the interpretive know-how of a four year old child. But our change in diet, locomotion, and subsequent physical adaptations were much more crucial in that they allowed for the major steps of modern intelligence to take place.
All in all, Early homo is important as the beginning of the homo lineage, but does not offer much more insight into how the modern mind evolved than modern chimps do. What is interesting is how we can trace later advancements of cognitive abilities to the changes in diet and locomotion seen in early Homo.
Dennet, D. 1988 The intentional stance in theory and practice.
Lieberman, Daniel E., Bernard A. Wood, and David R. Pilbeam. “Homoplasy and Early Homo: An Analysis of the Evolutionary Relationships of H. Habilis Sensu Stricto and H. Rudolfensis.” Journal of Human Evolution(1996): n. pag. Web.
Antón, Susan C. “Early Homo: Who, When, and Where.” Current Anthropology 53.S6, Human Biology and the Origins of Homo (2012): n. pag. JSTOR. Web. 07 May 2014. <http://www.jstor.org/stable/10.1086/667695?ref=search-gateway:ce4aeaf4d752f1b150cc72cb66af75d6>.
Tobias, Phillip V. “The Species Homo Habilis: Example of a Premature Discovery.” Finnish Zoological Publishing Board (1992): n. pag. Web.
Wood, Bernard. “Origin and Evolution of the Genus Homo.” Nature (1992): n. pag. Web.
Wood, Bernard. “Evolution in the Genus “Homo”” Annual Review of EcologyEvolution.And Systematics, Vol. 42 (2011): 47-69. JSTOR. Web. 07 May 2014. <http://www.jstor.org/stable/10.2307/41316980?ref=search-gateway:e6866311d46716ab920ce583c4cee279>.
Haeusler, Martin. “Body Proportions of Homo Habilis Reviewed.” Journal of Human Evolution (2004): n. pag. Web.
Gergely, György, and Gergely Csibra. “Teleological Reasoning in Infancy: The Naı̈ve Theory of Rational Action.” Trends in Cognitive Sciences7.7 (2003): 287-92. Print
Meltzoff, Andrew N. “Infant Imitation After a One Week Delay.”Developmental Psychology 24.4 (1988): n. pag. Web.
Premack, David. “The Infant’s Theory of Self-Propelled Objects.” Cognition16th ser. 36.1 (1990): n. pag. Web.
Leslie, Alan M. “Pretense and Representation.” Psychological Review 94.4 (1987): n. pag. Web.
Gergely, Gyorgy, and Gergely Csibra. “Taking the Intentional Stance at 12 Months of Age.” (n.d.): n. pag. Web.
Schwier, Christiane. “Rational Imitation in 12 Month Old Infants.” Infancy 10.3 (2006): n. pag. Web.
Woodward, Amanda L. “Twelve-Month-Old Infants Interpret Action in Context.” Psychological Science 11.1 (2000): 73-77. JSTOR. Web. 04 May 2014. <http://www.jstor.org/stable/10.2307/40063499?ref=search-gateway:35c1c7e19ba30c39d7d8fe171a065506>.
Weiss, Daniel J., and Laurie R. Santos. “Why Primates? The Importance of Nonhuman Primates for Understanding Human Infancy.” Infancy(2006): n. pag. Web.
Warneken, F., and M. Tomasello. “Altruistic Helping in Human Infants and Young Chimpanzees.” Science 311.5765 (2006): 1301-303. Print.
Tomasello, Michael. “A New Look at Infant Pointing.” Child Development78.3 (2007): 705-22. JSTOR. Web. 05 May 2014. <http://www.jstor.org/stable/10.2307/4620661?ref=search-gateway:2817d6d863d6ad295bb8878964a8ad49>.
Tomasello, Michael. “Why Don’t Apes Point?” Roots of Human Sociality: Culture, Cognition, and Interaction (2006): n. pag. Web.
Roth, G., and U. Dicke. “Evolution of the Brain and Intelligence.” Trends in Cognitive Sciences 9.5 (2005): 250-57. Print.
Carey, Susan. The Origin of Concepts. Oxford: Oxford UP, 2009. Print.
Hare, Brian, Josep Call, and Michael Tomasello. “Do Chimpanzees Know What Conspecifics Know?” Animal Behaviour 61.1 (2001): 139-51. Print.