Compare, contrast and evaluate the nativist and empiricist views of infant perception

Researchers and theorists have long been interested in whether perceptual abilities are predominantly inborn or are a product of learning processes. This question forms part of the wider nature-nurture debate in psychology. Psychologists on the ‘nature’ side of the debate, referred to as ‘nativists’, argue that the abilities are innate and arise from inherited genetic factors, which predetermine their development along the process of maturation, whilst on the ‘nurture’ side, ‘empiricists’ believe that abilities develop largely as a consequence of experience. In order to find sufficient support for either view, psychologists have investigated perceptual abilities in a number of different ways. Their aim to resolve the debate has included studies on human infants, sensory restriction in non-human infants, perceptual readjustment, and cross-cultural differences. This essay considers evidence from studies conducted on human infants' face, colour and pattern recognition, preference for complex and moving stimuli, and depth perception; it also aims to work towards a balanced conclusion in the nature-nurture debate.

The debate about the influence of heredity and environment in perception has a long history. The first nativists appeared in the 17th century, the earliest representatives were the French philosopher Decartes (1638, cited in Smith, Cowie and Blades, 2003) and the German philosopher Kant (1781, cited in Smith, Cowie and Blades, 2003). Both claimed that perceptual capacities, like space and depth perception, were inborn. Later, in the early 20th century, Gestalt psychologists further supported this view by claiming that certain perceptual skills exist from the moment of birth because of the constructional features of the nervous system, and that these skills develop through maturation and interaction with the environment. Furthermore, gestalt psychologists emphasising the importance of instincts, which are inborn and responsible for starting the process of development in neonates. They also claimed that infants are born with the ability to order and arrange their perceptual world.

The empiricist view was developed by Locke (1690, cited in Smith, Cowie and Blades, 2003), who was greatly influenced by the early Greek philosophers, and was opposed to the Descartes' rationalism. In contrary to Descartes, he put forward the idea of a 'tabula rasa' as the state in which humans enter the world. He asserted that perception is at first an unorganised and meaningless sensation, and that human knowledge and behaviour develops only through experience from sensation and unconditional reflexes that are inborn. Locke maintained that infants need to learn how to perceive; through repeated sensation, they form habits, which create judgement, which then modifies and enhances perception. Senses are seen as separate entities, which do not communicate with each other, because they are not yet linked. Locke's work greatly influenced James (1890, cited in Smith, Cowie and Blades, 2003), who maintained that what infants perceive about the world through their senses are nothing else-just a 'blooming and buzzing confusion'. The ability to discriminate among sensations, like smell, shapes, colours, tastes, noises and voices, temperature, hunger, etc, is a result of a long learning process. The development of neuroscience and appearance of systematic experimentation techniques in the 1950s provided many contrary evidence, by which Locke's theories were heavily criticised and mostly disproved.

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Piaget represented a more balanced view between the two extremist schools. On the one hand, a closely related theory to empiricism was Piaget's (1954, cited in Smith, Cowie and Blades, 2003) constructivism. On the other hand, Piaget's view of infants’ perception borrowed some properties from the nativist theory; such as the idea of the inborn capabilities for assimilation, accommodation, equilibration and organisation of schemas. The latter term refers to the inborn ability to co-ordinate existing schemas (cognitive structures) and blends them into more complex systems. He also further developed Locke's philosophical theory of learning from reflexes, and that the knowledge of the world is not innate, but progressively learnt through experience by constantly exploring the environment. As neonates' senses are not connected yet and hardly co-ordinated, he believed that objects do not become real entity until interaction between the senses happens by seeing, touching and tasting the objects. The results of constantly searching and experiencing the surrounding environment eventually lead to representation and objectification in the mind. Although the Piagetian stages of intellectual development are criticised as rigorous and not taking into consideration individual differences, it is still the most comprehensive theory of human development in psychology.

Until the 1950s, the empiricist view was the most influential in developmental psychology. Nativists initiated to study perceptual abilities in newborn infants, as the most direct way of assessing which perceptual abilities are inborn - assuming that the abilities are present at birth and have not been learnt in the womb. Although, this may sound obvious, researchers always faced difficulties when studying infant perception; for instance, infants could not tell them what they could perceive; they could easily become upset or distracted and then would not respond to the task; and the research method and process must always fulfil all the ethical requirements, therefore researchers were limited in the means. To resolve these difficulties, a range of techniques have been developed in the last fifty years, which allow them to observe and infer what infants can and cannot perceive; and they are ‘the preference technique’, ‘habituation’ and ‘conditioning’. These technical resolutions helped Frantz conduct the first experiment on two day old infants.

Fantz (1961, cited in Smith, Cowie and Blades, 2003) studied pattern recognition and the perception of faces. To help discover whether infants could discriminate patterns and forms, Fantz used a ‘prefrontal looking’ technique. This involves presenting infants with two or more different stimuli simultaneously. If the infant spends a significantly longer time looking at one stimulus rather than another, it can be concluded that the infant is able to distinguish between them, and that they prefer one to the other (spontaneous visual preference). Frantz found that two day old infants could discriminate between patterned and unpatterned shapes. Firstly, he tested 30 infants (aged 1 to 15 weeks) in a 'looking chamber' by presenting pairs of discs, on which were painted horizontal stripes, a ‘bull’s eye’, a checkerboard, a plain square, a cross, a circle and triangles. In the second experiment, infants (aged 4 days to 6 months) were shown three head-shaped flat objects. One showed a two-coloured stylised face, another presented a scrambled face pattern, and the third was painted black. Fantz discovered a preference for more complex stimuli over simple ones with infants spending more time looking at the human face. This suggested that an interest in complexity is inborn. On the other hand, perhaps it is a preference for faces that is in itself innate, which would make some sense in evolutionary terms. To support this assumption, Fantz's measured infants at all ages who spent significantly longer looking at the normal faces. The reliability of this finding can be questioned because the difference in preference was small and other researchers have failed to replicate Fantz’s findings. It could also be argued that familiarity with faces, especially which of an infant’s mother, is gained as a result of consistent and continuous reinforcement since birth, in which case learning could still play an important role.

Another researcher, Goren (1975, cited in Smith, Cowie and Blades, 2003) supporting the nativist view, found that infants have the ability to detect face-like stimuli from birth. He based his conclusion on an experiment, in which he moved three different type of face picture (a schematic, a scrambled and a blank outline) in an arc from one side of the newborn infant to the other side, measuring the length of time the infant looked at each picture. The infants could perceive the moving stimuli, and showed a preference to the moving schematic face. This finding seems to support both, the Gestalt psychologists' view and the Piagetian theory, namely that the infant's cognition is organised from birth. However, it cannot be ruled out that this preference is caused by the fact that a moving symmetrical pattern is more distinguishable from its background (painted or wallpapered walls) than a mixed-up one, and can also be more interesting. Johnson and his colleges (1991, cited in Smith, Cowie and Blades, 2003) confirmed Goren's findings with newborn infants, and also found that, from the age about three month this preference is not evident. The disappearance of this preference can be explained by the habituation to the presence of people, so from this age infants are instinctually looking for different, novel stimuli. Although, nowadays most psychologists would agree that these three skills (preference to complexity, movements and faces) are inborn, since this view seems to be supported by experiments, some empiricists are still sceptical about this and would say that newborns cannot process vision clearly. They are only able to see lighter and darker patches and their vision is not focused nor coordinated.

Bornstein (1976) used habituation to investigate colour perception in infants. This study was based on the finding that infants attend less to stimuli, which they recognise, rather to which they have become habituated. Presenting new stimuli immediately after familiar stimuli will tend to‘re-excite’ attention. In this way, Bornstein discovered that most babies possess noticeably normal colour vision by the age of two months. It is evident that infants can see from birth, although they have only a limited ability to detect colours. They also can focus to a distance of 8"-10", which is the distance between the mother's and infants' face whilst nursing. Adams and his colleagues (1994; cited in Smith, Cowie and Blades, 2003) found that infants at birth could only distinguish between red and white colours. According to Teller and his colleagues (1978; cited in Smith, Cowie and Blades, 2003), by the age of two months they become able to separate several other colours from white, including blue, orange, some purples and greens. It is also known that human infants show the ‘papillary reflex’ and ‘blink response’ at birth, which must show that very young infants can perceive brightness and movement to some extent and that these abilities are likely to be inborn. In conclusion, infants from their birth have a functioning and effective visual system, which is genetically determined. Initially the visual perception is limited to a certain extent, and rapidly develops in the first year of life. This limitation may have an important function, which helps the newborn to focus on the most important aspects of their environment during the first few month of life (Hainline, 1998; cited in Smith, Cowie and Blades, 2003).

Another area of neonate studies has focused on depth perception. Gibson and Walk (1960, cited in Smith, Cowie and Blades, 2003) constructed an apparatus in which infants were placed on a sheet of strong, transparent glass, below which was a checkerboard pattern. On the shallow side, the pattern was immediately below the glass, whilst on the deep side, the pattern was placed about four feet below, giving the impression of a considerable drop. The researchers placed the infant on the shallow side of the 'visual cliff' apparatus and watched his/her behaviour when called by the mother who was standing opposite, just beyond the deep side. Gibson and Walk argued that, if the infant was reluctant to crawl across onto the deep side, then it could be inferred that he/she had a depth perception and could predict danger. They found that most babies aged between 6 and 14 months would not crawl onto the deep side. This suggests that depth perception is innate. However, since infants needed to be at an age where they could crawl, it is also possible that they had learnt to perceive depth by this age. They may even have experienced falling. Consequently, Campos and his colleagues (1970, cited in Smith, Cowie and Blades, 2003) devised a method of assessing infants' performance at an age younger than 6 months. In the experiments, infants were placed (face down) on either the shallow or deep side of the visual cliff, and then moved to the opposite side, whilst monitoring the infant's heart beat rate. Campos and his colleagues found that their heart rates increased, or decreased, significantly when moved suggesting that the infants were able to detect the change. Hence, it seems likely that they could perceive the dimension of depth very early on – probably at birth. Nevertheless, empiricists would contradict this nativist view by pointing out the strong emotional link between the infant and the mother, whereby simply seeing the mother's anxiety would stress the infant and raise the heart beat, or stops him/her moving forward. In addition, testing newborn infants, who only can focus their vision between 8"-10", hence it would not be realistic to say that they perceived the four foot deep drop, but they surely could sense the support of the glass sheet, therefore the higher heart beat rate could be a result of other factors, such as not being able to see what was underneath, because the glass sheet was transparent or the discomfort from being placed face down on a glass sheet.

In general, studies of neonates suggest that many perceptual abilities, such as the detection of brightness, depth, and colour perception are innate, although these may not mature fully until some time after birth. Researchers face many difficulties when studying neonates; they cannot tell the researchers what they can see or feel, and it is not possible for ethical reasons to discover the full extent to which the environment may influence the development of perceptual abilities. Obviously, inducing fear or restricting their opportunities for perceptual learning cannot take place in experiments. For these reasons, Campos and his colleagues’ experiments would not receive ethical approval if conducted today.

To summarise, it seems clear that many perceptual abilities are inborn, but only can manifest themselves through maturation and experience. The opposite view is that complex abilities, like human face recognition, may be more dependent on learning. Until the 1950s the empiricist’s view was highly influential, so the rapid development of the neuroscience and research methods in studying infants the naitivist’s view became authoritative. Nowadays most psychologist agree with a more balanced view; that human infants are born with a wider range of perceptual abilities than empiricists have ever suggested, and that infants’ capability to learn quickly and adequetally from experience is greater than the nativists suggested (Gordon and Slatter, 1998, cited in Smith, Cowie and Blades, 2003). These kinds of scientific investigations are still difficult to instigate because of the ethical concerns; until new technologies are developed, conclusions suggesting exaggerating the nature or nurture side must be treated with caution.

Reference

Bornstein, M. H. (1976). Bornstein, M. H., Kessen, W., & Weiskopf, S. (1976). The categories of hue in infancy. Science, 191, 201-202.

Smith, P. K., Cowie, H. and Blades, M. (2003). Understanding Children’s Development. Oxford:Blackwell Publishing.