The use of sustainable technology is made or marred by the user’s behavior; the availability of the technology alone is not enough, as psychologist Cees Midden knows full well. “The benefits of sustainable technology are partly leaking away. If a more economical car is so comfortable that you almost automatically go faster, this will undo the benefits. Similarly, the construction of straight, wider roads will have a contrary effect.”

Midden, who will after almost 25 years say goodbye as professor at TU/e this week, will argue in his valedictory lecture that consumers must be subtly urged to make the right, sustainable choices. “Although you shouldn’t force people, you can make sure that the most sustainable option is the easiest, the most fun or the cheapest. Or that it is the only option, of course”. One way in which this can be done is to make technology give smart feedback to the user. “You already see this in many newer cars; they indicate graphically how fuel-efficient your way of driving is at a certain moment.”

If the artificial agent feels like a person, it is almost impossible to ignore its feedback

Washing machines, too, could give information about the energy consumption of each washing program. Many years ago Midden conducted experiments in which he and his colleague Jaap Ham made a small robot, Victor, which had been developed by Philips, give feedback to human subjects who had to carry out a certain washing task – clean muddy jeans. “Among other things, they had to set the temperature and centrifuge speed. Victor gave comments such as ‘well done’, ‘fantastic’, or ‘lousy’. Quite simple, but at once quite effective. Even though people indicate that they would not take such an artificial agent seriously. The opposite turns out to be true.”

When an artificial agent (an ‘artificial person’) gives the right social signals, the impact of its feedback becomes bigger, as Midden’s research has shown. Simply indicating the number of kilowatt hours that each washing program would cost – which may be more obvious than the use of an artificial agent – proves to be far less effective. The psychologist thinks that allowing such a number to sink in requires another type of attention than what is needed to process a comment from a robot. And often people are simply incapable of mustering such analytical attention. However, if the artificial agent feels like a person, it becomes almost impossible to ignore its feedback. The fact is we are quite sensitive to the opinions of other persons, says Midden. “Even if we know that they may not be serious, but are consciously flattering us or playing up to us.”

Cees Midden’s valedictory lecture will take place in the Blauwe Zaal at 16.00 hours on Friday October 30. Preceding it, a symposium about ‘Persuasive Technology and Sustainability’ will be held at the same location. Both events are freely accessible. For the symposium it is necessary to register (via hti@tue.nl).