September 2006

Prof. Köster, sensory research is quite a young field of research. How did you personally get involved with this subject?

In 1956 I studied perception psychology at Utrecht University. I was mainly interested in visual perception. One day my Professor, Hans Linschoten, received a visit from Dr O. Wouters, a food chemist who worked at TNO (Organisation for Applied Scientific Research in the Netherlands). He told Linschoten that the food industry often tested their products by getting people to taste them and then used a some of the resulting statistics to choose what they thought would be the best product for the market. In his view, people were used as a measuring tool in this procedure, and as a scientist he would nevaer use such a tool without fully understanding how it functions. Therefore, he had come to the conclusion that understanding the possibilities and limitations of the human component in testing was a psychological problem, and thus he had came to Linschoten for help and co-operation.

Linschoten remembered that I had started my studies in chemistry before switching to psychology, and asked me whether I was interested. I accepted, and consequently worked for many years at the University in co-operation with TNO. Dr. Wouters, who had the original – and for a chemist in those days, most remarkable – insight, supported my research in every possible way. He also taught me a very important lesson: applied research (especially when it pertains to psychology) is often much more difficult, much more interesting, and even much more fundamental than the “fundamental” research that tests hypothetical constructs in the laboratory, yet never verifies whether these also apply in reality. Applied research shows you the complexities of the many behavioural interactions and points out the limitations of your theories and ideas.

I am still grateful for that lesson, and although I always try to find the underlying mechanisms that determine behaviour, I also try to keep an eye out for the ecological validity of my research.

Which are the most important and the most interesting research questions you have been working on?

There are several I'd like to mention:

First is the integration of perception, memory, emotions and motor activity in the expectations and unconscious meaningful interpretations of situations that characterise our “stream of behaviour” (not of consciousness). In the field of sensory consumer research, perception is still too oftenseen as playing an essentially passive role, and as a consequence, there is a conviction that it is the stimulus that determines behaviour. In reality, we are never without unconscious expectations, intentions, and actions that determine the meaning of the stimulus in a given situation. Finding ways to explore and tap this unconscious integration and to show how it expresses itself in behaviour is the true task of psychology, and of sensory consumer science for that matter.

I am convinced that it is necessary to get away from sensory consumer research in which the consumer is seen as a unitary person. Instead, the consumer should be viewed as a variety of personalities that react differently in different situations. This means that it is more instructive to categorise eating and drinking situations (not environments, but meaningful situations) that consumers uniformly share. Further developing methods that give analytical insights into such situations seems important.

There needs to be more research on the differences between perceptual and memory function of the various senses. We need more study on the relationship between the senses and the objects they perceive to help to understand their ecological meaning and their possible evolutionary origin. For instance, we have found striking differences between the way vision and olfaction work. In vision, identification and verbal naming play important roles in both perception and recognition memory. In contrast, in olfaction, detection of differences and noticing changes in odour are extremely important, while the identification and naming of odours play no role in most of our daily lives. We are notoriously bad at identification of odours and flavours, but we can easily detect slight off-odours in a familiar product. This is an important distinction between the two senses, one that has consequences for the way we should do our research. In fact, we often find that descriptive panels (who typically learn to identify odours and need to be thoroughly trained for it) can not detect a difference between two versions of a product, whereas consumers participating in blind tests clearly prefer one over the other.

Which of your findings do you consider relevant to the industry and to consumers in everyday life?

I have found that when consumer research concentrates on looking for the most-liked new product, it often leads to the creation of product flops and shortens the product life cycle. New products that are somewhat more complex than the most-liked ones have a much better chance of long-term acceptance.

It is also necessary to develop methods that do not put the consumer in an unnatural position of overanalysing when judging the product or it’s “appropriateness” in a given situation.

What role does the European Sensory Network play for sensory consumer research, and why did you help found this organisation?

For sensory research, ESN is an important platform for co-operative research and integrated services to the industry. It was founded for two principal reasons. In contrast to companies in the US, it is grounded on mutual assistance instead of competition. In addition, Europe is a continent with great regional diversity of products and traditions. There was and is a need to understand this diversity and how it relates to the industry, and ESN fulfils this need.

Over the years, ESN has also contributed to the development and spread of better sensory and consumer research methodology and techniques. As a rather limited and closed group in the early years of its existence, it profited from an optimal climate for mutual understanding between partners from different national and scientific backgrounds. As ESN grows, it is of great importance to safeguard these values while admitting more European organisations and seeking out a wide variety of (e.g industrial) partners.

What role do you think sensory consumer research will play in the future?

Once we understand the complex interactions of the conscious and unconscious determinants pertaining to food-choice behaviour, it will be possible to influence eating habits – both as they are formed and as they change – much more effectively than is the case today. Currently, most campaigns geared towards promoting a healthy diet are too slow and are often unsuccessful.

Descriptive sensory analysis will retain its original function, i.e. as an tool for product development and product control that helps the industry to translate perceptual properties into product properties. However, I suspect that the importance given to the traditional sensory properties in food choice will diminish. Instead, the intestinal feelings that accompany eating and drinking behaviour, and memories linking these feelings to sensory properties and consumer expectation, will probably gain in importance. Along with this, the traditional hedonic evaluation methods used in central location tests and in-home-use tests will probably disappear eventually, making room for new methods.

In the future we will have to orient our research more on the ecological validity of the research methods. Since we have learned over the last two decades that people are seldom conscious of their true motives and feelings, we will have to find better ways to predict their behaviour than by just asking them explicit questions about their attitudes, intentions and feelings. Instead we should observe their behaviour, their choices in specific situations, and the unconscious expression of their feelings shown through their body language, facial expressions, product inspection time, time taken to decide, etc.. We should also further investigate whether it is possible to have people simulate situations by imagining them and then making choices. These methods will be exploited e.g. in the “Restaurant of the Future” that is being installed at the Center for Innovative Consumer Studies (CICS) at Wageningen University and Research. The methods used there will be combined with research on the role of memory and expectation in food perception in the broadest sense (i.e. including memories not only of sensory properties, but also of post-ingestional feelings, eating situations, etc.).

In general, it seems to me that studying expectations and memories of foods could become more important for the understanding of eating, drinking, and food choice behaviour than the direct perception of the food. After all, food choice is a learned behaviour.

Some people are very critical of consumer research in general. They are afraid that when the researchers have a good understanding of the results the industry could manipulate the consumer subconsciously, e.g. by marketing “irresistible” products that are turn out to be unhealthy. Is this a real danger?

Of course, it is true that such knowledge could be misused as well. But I think that as we learn more about the early determinants of eating and drinking behaviour and food choice, it will be possible to help children develop an interest in food variety at a very early age – an interest that they will retain throughout their lives. This supposition is backed up by the longitudinal work of Sophie Nicklaus in Dijon. It is important not to tie people to particular products: the healthier approach is to look for variety in food choices. At the same time, such knowledge would make it possible to recognise and criticise possible misuses of research information by the industry. When the use of persuaders is no longer hidden, they can be more readily attacked and exposed as abusive practices.

Thank you, Prof. Köster.

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