People's opinions are affected by what their eyes are focusing on in the same instant they make moral decisions, according to a recent study.

Researchers at Lund University, University College London (UCL) and the University of California, Merced, managed to influence people's responses to questions such as "is murder defensible?" by tracking their eye movements. When the participants had looked at a randomly pre-selected response long enough, they were asked for an immediate answer. Fifty-eight percent chose that answer as their moral position.

"In this study we have seen that timing has a strong influence on the moral choices we make. The processes that lead to a moral decision are reflected in our gaze. However, what our eyes rest on when a decision is taken also affects our choice," Philip Pärnamets, one of the authors of the study, said in a statement.

Researchers studied in real time how people deliberate with themselves in difficult moral dilemmas. The participants had no idea that the researchers were carefully monitoring how their gaze moved in order to demand an answer at the right moment. The results showed that the responses were systematically influenced by what the eye saw at the moment an answer was demanded.

"What is new is that we have demonstrated that if eye movements are tracked moment by moment, it is possible to track the person's decision-making process and steer it in a pre-determined direction", said Petter Johansson, a reader in cognitive science at Lund University.

The study is the first to demonstrate a connection between gaze and moral choices, but it is based on previous studies which have shown that for simpler choices, such as choosing between two dishes on a menu, our eye movements say what we will eat for dinner before we have really decided.