Opting for the new may have an evolutionary benefit
Scientists have located a region of the brain that encourages humans to indulge in adventurous behaviour.
Sophisticated scans showed the region, located in a primitive area of the brain, is activated when people choose unfamiliar options.
The researchers believe this suggests that taking a chance is an ancient human trait that may have given humans an evolutionary advantage.
The University College London study features online in the journal Neuron.
The research took place at UCL's Wellcome Trust Centre for Neuroimaging.
Volunteers were shown a selection of images with which they had already been made familiar.
Each card had a unique probability of reward attached to it and, over the course of the experiment, the volunteers would be able to work out which selection would provide the highest rewards.
However, when unfamiliar images were introduced the researchers found that volunteers were more likely to take a chance and select one of these options than continue with their familiar - and arguably safer - option.
Using fMRI scanners, which measure blood flow in the brain to highlight which areas are most active, the researchers showed that when the subjects selected an unfamiliar option an area of the brain known as the ventral striatum lit up, indicating that it was more active.
The ventral striatum is in one of the evolutionarily primitive regions of the brain - suggesting that the process can be advantageous and will be shared by many animals.
Lead researcher Dr Bianca Wittmann said: "Seeking new and unfamiliar experiences is a fundamental behavioural tendency in humans and animals.
"It makes sense to try new options as they may prove advantageous in the long run.
"For example, a monkey who chooses to deviate from its diet of bananas, even if this involves moving to an unfamiliar part of the forest and eating a new type of food, may find its diet enriched and more nutritious."
Potential for exploitation
The researchers believe that making a new choice that turns out to be beneficial stimulates release of mood-changing chemicals such as dopamine, which make it more likely that we will continue to be adventurous in the future.
However, the researchers said that making new choices was often a fruitful strategy and also potentially made us more vulnerable to exploitation - for instance by the advertising industry.
Dr Wittmann said: "I might have my own favourite choice of chocolate bar, but if I see a different bar repackaged, advertising its 'new, improved flavour', my search for novel experiences may encourage me to move away from my usual choice.
"This introduces the danger of being sold 'old wine in a new skin' and is something that marketing departments take advantage of."
Professor Nathaniel Daw, now at New York University, who also worked on the study, said rewarding the brain for novel choices could have a more serious side effect.
"In humans, increased novelty-seeking may play a role in gambling and drug addiction, both of which are mediated by malfunctions in dopamine release."
Professor Seth Grant, of the Wellcome Trust Sanger Institute, said the ability to recognise novelty pre-dated the evolution of the striatum, as it had been identified in primitive invertebrates, such as the octopus, which do not have the structure.
However, he said it was probable that the striatum had helped more sophisticated species, including man, to refine the ability.