Limits...
Visual recognition of age class and preference for infantile features: implications for species-specific vs universal cognitive traits in primates.

Sato A, Koda H, Lemasson A, Nagumo S, Masataka N - PLoS ONE (2012)

Bottom Line: When analyzing the side of the first look, JM subjects significantly looked more often at novel images.CM subjects showed no difference in the side of their first look, but looked at infant JM images longer than they looked at adult images; the fact that CMs were totally naïve to JMs suggested that the attractiveness of infant images transcends species differences.Our results suggest not only species-specific processing for age class recognition but also the evolutionary origins of the instinctive human perception of baby cuteness schema, proposed by the ethologist Konrad Lorenz.

View Article: PubMed Central - PubMed

Affiliation: Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan.

ABSTRACT
Despite not knowing the exact age of individuals, humans can estimate their rough age using age-related physical features. Nonhuman primates show some age-related physical features; however, the cognitive traits underlying their recognition of age class have not been revealed. Here, we tested the ability of two species of Old World monkey, Japanese macaques (JM) and Campbell's monkeys (CM), to spontaneously discriminate age classes using visual paired comparison (VPC) tasks based on the two distinct categories of infant and adult images. First, VPCs were conducted in JM subjects using conspecific JM stimuli. When analyzing the side of the first look, JM subjects significantly looked more often at novel images. Based on analyses of total looking durations, JM subjects looked at a novel infant image longer than they looked at a familiar adult image, suggesting the ability to spontaneously discriminate between the two age classes and a preference for infant over adult images. Next, VPCs were tested in CM subjects using heterospecific JM stimuli. CM subjects showed no difference in the side of their first look, but looked at infant JM images longer than they looked at adult images; the fact that CMs were totally naïve to JMs suggested that the attractiveness of infant images transcends species differences. This is the first report of visual age class recognition and a preference for infant over adult images in nonhuman primates. Our results suggest not only species-specific processing for age class recognition but also the evolutionary origins of the instinctive human perception of baby cuteness schema, proposed by the ethologist Konrad Lorenz.

Show MeSH

Related in: MedlinePlus

Schematic representation of the VPC paradigm for the (A) adult/infant (AI) condition, and the (B) infant/adult (IA) condition.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368701&req=5

pone-0038387-g001: Schematic representation of the VPC paradigm for the (A) adult/infant (AI) condition, and the (B) infant/adult (IA) condition.

Mentions: In Experiment 1, JMs were used both as subjects and as stimulus images in the VPC tasks. The tasks included two order conditions: adult-infant (AI) and infant-adult (IA). In the AI condition, an adult stimulus was presented in the familiar phase and an infant image was used as the novel stimulus in the test phase; the stimuli were reversed in the IA condition. Figure 1A shows a schematic representation of the fixation, familiarization, re-fixation, and test phases for the AI condition in a single VPC trial.


Visual recognition of age class and preference for infantile features: implications for species-specific vs universal cognitive traits in primates.

Sato A, Koda H, Lemasson A, Nagumo S, Masataka N - PLoS ONE (2012)

Schematic representation of the VPC paradigm for the (A) adult/infant (AI) condition, and the (B) infant/adult (IA) condition.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368701&req=5

pone-0038387-g001: Schematic representation of the VPC paradigm for the (A) adult/infant (AI) condition, and the (B) infant/adult (IA) condition.
Mentions: In Experiment 1, JMs were used both as subjects and as stimulus images in the VPC tasks. The tasks included two order conditions: adult-infant (AI) and infant-adult (IA). In the AI condition, an adult stimulus was presented in the familiar phase and an infant image was used as the novel stimulus in the test phase; the stimuli were reversed in the IA condition. Figure 1A shows a schematic representation of the fixation, familiarization, re-fixation, and test phases for the AI condition in a single VPC trial.

Bottom Line: When analyzing the side of the first look, JM subjects significantly looked more often at novel images.CM subjects showed no difference in the side of their first look, but looked at infant JM images longer than they looked at adult images; the fact that CMs were totally naïve to JMs suggested that the attractiveness of infant images transcends species differences.Our results suggest not only species-specific processing for age class recognition but also the evolutionary origins of the instinctive human perception of baby cuteness schema, proposed by the ethologist Konrad Lorenz.

View Article: PubMed Central - PubMed

Affiliation: Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan.

ABSTRACT
Despite not knowing the exact age of individuals, humans can estimate their rough age using age-related physical features. Nonhuman primates show some age-related physical features; however, the cognitive traits underlying their recognition of age class have not been revealed. Here, we tested the ability of two species of Old World monkey, Japanese macaques (JM) and Campbell's monkeys (CM), to spontaneously discriminate age classes using visual paired comparison (VPC) tasks based on the two distinct categories of infant and adult images. First, VPCs were conducted in JM subjects using conspecific JM stimuli. When analyzing the side of the first look, JM subjects significantly looked more often at novel images. Based on analyses of total looking durations, JM subjects looked at a novel infant image longer than they looked at a familiar adult image, suggesting the ability to spontaneously discriminate between the two age classes and a preference for infant over adult images. Next, VPCs were tested in CM subjects using heterospecific JM stimuli. CM subjects showed no difference in the side of their first look, but looked at infant JM images longer than they looked at adult images; the fact that CMs were totally naïve to JMs suggested that the attractiveness of infant images transcends species differences. This is the first report of visual age class recognition and a preference for infant over adult images in nonhuman primates. Our results suggest not only species-specific processing for age class recognition but also the evolutionary origins of the instinctive human perception of baby cuteness schema, proposed by the ethologist Konrad Lorenz.

Show MeSH
Related in: MedlinePlus