The evolution of quantitative sensitivity.

The ability to represent approximate quantities appears to be phylogenetically widespread, but the selective pressures and proximate mechanisms favouring this ability remain unknown. We analysed quantity discrimination data from 672 subjects across 33 bird and mammal species, using a novel Bayesian model that combined phylogenetic regression with a model of number psychophysics and random effect components. This allowed us to combine data from 49 studies and calculate the Weber fraction (a measure of quantity representation precision) for each species.

Differences in greeting behaviour towards humans with varying levels of familiarity in hand-reared wolves ().

Socialized wolves' relationship with humans is a much debated, but important question in light of dog domestication. Earlier findings reported no attachment to the caretaker at four months of age in a Strange Situation Test, while recently attachment to the caretaker was reported at a few weeks of age in a similar paradigm. To explore wolf-human relationship, we analysed behaviours of hand reared, extensively socialized wolves towards four visitor types: foster-parents, close acquaintances, persons met once before, and complete strangers during a greeting episode.

Role of mental representations in quantity judgments by jackdaws (Corvus monedula).

The representation of quantity by the preverbal or nonverbal mind is a question of considerable interest in the study of cognition, as it should be generally adaptive to most animals to be able to distinguish quantity. We already know that some primate species and human infants represent and enumerate objects in similar ways. Considerable data also exist concerning such abilities in birds.

A study of behaviour profiles among intellectually disabled people in residential care in Hungary.

The authors investigated the behavioural dimensions of 269 intellectually disabled (ID) people in residential care in specialized institutions in Tolna county (South-West Hungary) with the aim of screening the frequency and severity of the relevant behavioural symptoms associated with intellectual disability and depending on the level of intellectual impairment. Only 120 residents had an International Classification of Disease (ICD) diagnosis of "mental retardation (MR)" and a valid IQ grading either by means of the Hungarian standard version of the HAWIK or by the coloured Raven test. 4 IQ groups were created: borderline (B), mild (MID), moderate (MOD) and profound (PID) intellectual disability subgroups.