1,721,270 research outputs found
The psychology of sharing: an evolutionary approach
No full textThis thesis takes an evolutionary perspective on human psychology. To
the extent that inherited tendencies shape behaviour, their design will be
fitted to the social environments prevailing as Homo sapiens evolved, in
foraging groups, the nearest modem equivalent being hunter-gatherers.
From ethnographies of hunter-gatherers, food-sharing and counterdominance
were identified as universal. Food-sharing was more thorough
than is explicable purely by kinship or reciprocation; one functional effect
was to even out the supply of valuable high-variance food. In contrast with
the social systems of the other great apes, counter-dominance spread
influence widely, preventing the emergence of dominant individuals who
could obtain resources disproportionately. Potential paths for the evolution of
egalitarian tendencies are discussed.
Two falsifiable hypotheses were generated from this perspective. First,
sharing will facilitate risk-taking. The predicted effect was confirmed at high
risk levels, similar to those faced by hunters. Given that during evolution risk
was reduced primarily by social means, social as well as rational factors are
treated by the evolved brain as relevant to risky decisions. It is argued that
this result may suggest a new perspective on the Group Polarisation
experiments.
The second hypothesis tested was that an egalitarian environment will
produce beneficial effects on individual and social behaviour. The data
collected were consistent with the hypothesis: a comparison between three
Italian towns showed that measures of health (including cardiovascular
mortality), education, social involvement, crime and social perceptions were
significantly more positive where co-operatives employed a larger percentage
of the population.
The evolutionary perspective showed its value as a means of generating
novel testable hypotheses
"Over-imitation": A review and appraisal of a decade of research
Full text linkAfter seeing an action sequence children and adults tend to copy causally relevant and, more strikingly, even perceivably unnecessary actions in relation to the given goal. This phenomenon, termed “over-imitation”, has inspired much empirical research in the past decade as well as lively theoretical debate on its cognitive underpinnings and putative role in the transmission of cultural knowledge. Here, we offer a comprehensive review of the existing literature to date, accompanied by a table including concise information on 54 published studies testing over-imitation in different species, age groups and cultures. We highlight methodological issues related to task and context that influence over-imitation rates and that should be carefully considered in study designs. We discuss the cognitive and motivational processes underlying and contributing to over-imitation, including normative action parsing, causal reasoning, motives of affiliation and social learning as well as their complex interplay. We conclude that despite the apparent irrationality of over-imitation behavior, recent studies have shown that its performance depends on the specific task, modeled actions and context variables, suggesting that over-imitation should be conceptualized as a contextually flexible and, in fact, a normally highly functional phenomenon
Social learning in mother-reared and "enculturated" capuchin monkeys
No full textThis thesis explores social learning in mother-reared and “enculturated” capuchin
monkeys (Cebus apella). At the outset a framework for understanding the social
influence on learning is discussed, followed by a review of the social and cognitive
abilities of capuchin monkeys, establishing the rationale for studying social learning in
this species.
Studies of wild capuchins suggest an important role for social learning but
experiments with captive subjects have generally failed to support this. Some potential
reasons for the lack of evidence in experimental settings are given.
An example of using the two - method design to test social learning in acquiring
behaviour by enculturated subjects is addressed. The results are related to findings with
other species tested with a similar apparatus. Before testing mother-reared monkeys, an
observational study of the object manipulation and tool-use repertoire of the subjects was
carried out in order to facilitate the design of suitable social learning tasks for these
monkeys.
The first empirical study in Chapter 6 reports results of experiments with the
enculturated and mother-reared capuchin monkeys employing the two -action method
together with a third control group. The enculturated monkeys exhibited high fidelity
copying that included the specific tool use technique witnessed while opening the
foraging box. Mother-reared monkeys exhibited fidelity at a lower level, tending only to
re-create the results the model had achieved.
The second empirical study in Chapter 7 tested whether capuchin monkeys could
show cumulative cultural learning manifested in the ability to switch from an established
mode of manipulating a dipping box to a complex yet more advantageous one. Both
populations were able to do so. The enculturated monkeys, as in the previous study,
showed higher fidelity copying of the model.
The last experiment was a preliminary study employing the “do as I do” method
which was carried out with four of the enculturated monkeys. It provides suggestive
evidence for at least one monkey's understanding of the task.
The results of the studies are discussed in relation to previous experimental
research as well as to data from capuchin monkeys in nature. The possible role of
enculturation in social learning ability is considered
Foraging strategies, diet and competition in olive baboons
No full textSavannah baboons are amongst the most intensively studied taxa
of primates, but our understanding of their foraging
strategies and diet selection, and the relationship of these
to social processes is still rudimentary. These issues were
addressed in a 12-month field study of olive baboons (Papio
anubis) on the Laikipia plateau in Kenya.
Seasonal fluctuations in food availability were closely
related to rainfall patterns, with the end of the dry season
representing a significant energy bottleneck. The
distribution of water and of sleeping sites were the
predominant influences on home range use, but certain
vegetation zones were occupied preferentially in seasons when
food availability within them was high.
The influence of rainfall on monthly variation in dietary
composition generally mirrored inter-population variation.
Phytochemical analysis revealed that simplistic dietary
taxonomies can be misleading in the evaluation of diet
quality. Food preferences were correlated with nutrient and
secondary compound content. The differences between males and
females in daily nutrient intakes were smaller than expected
on the basis of the great difference in body size; this was
partly attributable to the energetic costs of reproduction,
and possibly also to greater energetic costs of
thermoregulation and lower digestive efficiency in females.
A strongly linear dominance hierarchy was found amongst the
adult females. Dominance rank was positively correlated with
food ingestion rates and daily intakes, but not with time
spent feeding or with dietary quality or diversity. In a
provisioned group, high-ranking females occupied central
positions, while low-ranking females were more peripheral and
were supplanted more frequently. In the naturally-foraging
group, the intensity of competition was related to the pattern
of food distribution, but not to food quality, and was greater
in the dry season than in the wet season. The number of
neighbours and rates of supplanting were correlated with rank,
and evidence was presented that high-rankers monopolised
arboreal feeding sites
Imitation, play and theory of mind in autism : an observational and experimental study
No full textThis observational and experimental study takes the Intersubjectivity Theory
of Rogers and Pennington (1991), as the guiding line by which to investigate
imitation in autism. A deficit in imitation in early childhood is the principal aspect of
this theory which distinguishes it from other major theories such as those of Baron-
Cohen et al. (1985) and Hobson (1986).
With much debate over the existence of a general deficit in imitation, this
study aimed first to test for different types of imitation (including those
differentiated by Piaget (1962), such as vocal, immediate and deferred imitation) and
second, to examine other deficits linked to imitation in Roger and Pennington's
theory - emotion perception, joint attention, theory of mind and play. The effect of
age was also investigated. Rogers and Pennington (1991) predicted that young
autistic children would show a profile of deficits including impaired imitation,
emotion sharing, joint attention and pretend play while older children and adults
would show impaired "theory of mind", emotion sharing and language pragmatics,
relative to controls.
In an observational study autistic children and adults showed less social
interaction with peers, more manipulative play, less symbolic play in some
comparisons and less evidence of mental state understanding but few differences in
imitation, compared to children with learning disabilities and normal 3-4 year old
and 5-6 year old children.
Virtually the same samples were then tested experimentally for the ability to
imitate. This was done for (1) elicited imitation (including vocal, simple body
movements and symbolic actions, with and without objects), (2) spontaneous,
problem-solving imitation and (3) deferred imitation. In addition, spontaneous,
elicited and instructed play was tested and visual perspective-taking, joint attention,
false-belief and emotion recognition. No general deficit for imitation in school-age
autistic children and autistic adults was found, although a younger group (CA 4 - 7
years) of autistic children did significantly worse on all aspects of the task. Scores
were lower on deferred imitation and on spontaneous, problem-solving imitation for
the autistic groups and certain categories of actions in the elicited task proved more
difficult for the autistic children, namely those requiring symbolic ability.
Previous findings on joint attention, false-belief and emotion perception
were, for the most part, confirmed, although no links between any of these
behaviours and imitation were evident from examination of individual profiles. In
addition, a picture of inconsistency across tasks emerged. However, some evidence
was found for Rogers and Pennington's theory at a crude level, in that it was the
youngest children who had most problems with imitation, symbolic play, and
emotion recognition, relative to controls. It is concluded that although imitation may
be lacking in early autistic development, Rogers and Pennington's theory may not be
an altogether satisfactory way of explaining its contribution to the autistic disorder
and is, in fact, very difficult to test
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Feeding, ranging and social organisation of the Guinea baboon
No full textBefore this study, the Guinea or Western baboon, Papio papio, was almost unknown in its natural environment. This thesis reports a nineteen-month field study of two troops of P. papio carried out in south-eastern Senegal. The monkeys were followed on foot, and aspects of their feeding, ranging and social behaviour were recorded.
The troops were censused whenever possible. Both study groups, and other troops in the area, were found to be unusually large by comparison with other known troops in the genus, and although their age-sex compositions were not exceptional, there was some indication that recruitment into the adult population was low.
The activity budgets of both troops were similar, and members of both troops spent more time moving and feeding in the dry season than they did in the wet, when they spent more time in social behaviour. These differences were probably related to seasonal changes in productivity, which were large, since no rain feel in six months of the year.
The home range of one of the study troops covered about 45 to 50 square kilometres, while the other troop, whose home range was less well known, ranged over about 18 to 20 square kilometres. There were no seasonal differences in the mean distance travelled per day by either troop, although there was great daily variation about the mean of roughly 8 kilometres. This distance was greater than that travelled by most other troops of baboons, and was ascribed to low productivity in the dry season and large troops in the wet. The troops visited some habitats more frequently than they did others, and moved more slowly through those that they visited frequently than through those that they visited frequently than through those they visited less frequently. In the dry season both troops visited areas in which there was relatively dense shade more frequently than they did areas with little shade. In the wet season they avoided areas in which variability was poor.
Sleeping sites were found to have a profound influence on the ranging patterns of the baboons, with usage of the home ranges being inversely proportional to the square of the distance from the nearest sleeping site. The baboons apparently chose to sleep in trees which afforded them protection against predation. The sleeping sites were restricted to places in which there was permanent water.
The baboons were largely frugivorous. In this they resembled baboon troops studied in other areas. Their diet changed throughout the year, as various plants fruited or seeded, and was more diverse in the wet season, when a wider variety of foods was available. More than a hundred different food items were known to be eaten, and the number of known food types increased throughout the study. Animals in their diet were mostly invertebrates found beneath boulders, but some vertebrates were also eaten.
The social organisation and mating system of these baboons were compared with those of the other baboons, including Theropithecus gelada. It was unlikely that they lived in a society in which adult females were constrained to mate with only one male, as are females in two other species of baboon. Instead, there appeared to be competition for sexual partners, with the formation of consortships between adults during the time of the female’s oestrus. Adult males groomed each other in this species, which is uncommon in baboons with competitive mating, except at times of stress
Social complexity in a large and small group of olive baboons
No full textGroup size is known to correlate with various indices of brain size in the primates. The possibility that increases in group size foster social complexity forms the central empirical topic of this thesis. A ten month field study of olive baboons, Papio cynocephalus anubis, was carried out on the Laikipia Plateau, Kenya. Data were collected on a wide range of social behaviours in two troops, one smaller than the mean group size for Papio and one larger.
The concepts of complexity and social complexity are critically examined with a view to their quantification in behaviour and cognition. The status of social complexity in the debate concerning the evolution of high intelligence in the Primate Order is discussed. Dimensions of social complexity are developed and then investigated empirically.
Females in the two troops showed similar grooming frequencies and grooming network sizes. However, the troops differed in the patterning of their grooming with respect to rank: individuals in the small troop groomed those of high rank, individuals in the large troop groomed those of rank similar to themselves.
Cluster analysis of spatial proximities showed no sign of cliquishness in either troop.
Females formed associations with particular males ('friendships') in both troops but there were no clear differences in either the number or stability of these associations.
The rate of interaction was higher in the large troop, but, proportional to total interaction rates, the rates of agonistic and polyadic interactions were not. The rate of interaction was higher for adult and sub-adult females than for adult and sub-adult males. In comparison, the proportion of interactions that were agonistic was greater for the adult and sub-adult males.
The variability of response to affiliation that individuals faced was the same across the two troops. Males, however, faced more variability than did females largely because of a high number of avoidant responses.
The absence of strong differences in social complexity between differently sized troops suggests that, proximally, cognitive complexity limits social complexity. Thus, interspecific comparisons may prove to be the most fertile area of research into complexity in the future
- …
