Baku, October 26 (AZERTAC). In the shop window gleams the coolest pair of shoes ever. Despite being able to afford them, some people will walk away, while others — though the purchase blows a hole in their personal finances — grab the kicks anyway, according to Lifescience.

We all have to spend money for necessities, such as groceries or rent. Occasionally, we also indulge on unhealthy treats and entertainment. Two contrary sorts of people, however, struggle to open their wallets even for things they really need – "tightwads" – while others can`t stop their shopping sprees – "spendthrifts."

Tightwads spend less than they should," said George Loewenstein, a professor of economics and psychology at Carnegie Mellon University. "They recognize that they should be spending more for their own wellbeing. The spendthrifts are the opposite. They spend more than they should spend by their own self-definition." [Read: The Truth About Shopaholics]

Studies have revealed a possible basis in the brain for why money burns a hole in some peoples` pockets while the mere thought of spending makes others grimace. Understanding why people under- and over-spend can help with ensuring they don`t unduly burden themselves – or their bank accounts – when making a purchase.

To gauge how many people qualify as spendthrifts or tightwads, Loewenstein and his colleagues surveyed more than 13,000 people, beginning back in 2004. Respondents reported how their scrimping and splurging diverged from their desired spending habits.

The researchers reported in a 2008 study that 3,248 respondents proved to be tightwads and 2,046 were spendthrifts. Percentage-wise, that works out to about 25 and 16 percent of the general population, respectively.

To get a sense of what happens in our brains when we consider dipping into the bank account, Loewenstein and colleagues used functional magnetic resonance imaging, or fMRI. This brain scanning technique monitors blood flow to areas in the brain activated when performing a task.

When study subjects looked at a desirable item, such as chocolate candies, their brains produced a starkly different response than when viewing the item`s price tag.

The key reward center the researchers saw light up was the nucleus accumbens, which plays a key role in pleasurable acts from having sex to hearing music. The specific pain-and-disgust region involved was the insula, which activates upon smelling foul odors or experiencing social exclusion, among other situations.

The findings suggest that that the emotional pain or anxiety of actually having to pay for an item works to keep our pleasure seeking in check.

In some people, the researchers think, this mental anguish is so strong that it overrides rational deliberation; these people are tightwads, and they don`t buy something even when they know they should.

For a spendthrift, the pain of throwing money around does not register in the brain like it does for other people.