An analysis of three US studies and one from Britain found that the average pay difference for two workers was £500 for every inch between them.

The University of Florida study said that this could amount to "hundreds of thousands" over the course of a career.

It said bosses saw taller people as more competent - and their higher self-confidence could also boost pay.

Professor Tim Judge, who led the study, compared people of the same age and sex who were different heights.

He found that each inch in height added $789 (£471) to the annual pay packet - so someone who is five feet five inches would be paid over $5,000 (£3,000) less than someone who is six foot tall.

Tall fortune

Professor Judge said: "If you take this over the course of a 30-year career and compound it, we're talking about literally hundreds of thousands of dollars of earnings advantage that a tall person enjoys.

When humans evolved as a species and still lived in the jungles or the plain, they ascribed leader-like qualities to tall people because they thought they would be better able to protect them Professor Tim Judge, University of Florida

"These findings are troubling in that, with a few exceptions such as professional basketball, no-one could argue that height is an essential ability required for job performance nor a bona fide occupational qualification."

When supervisors were quizzed about how they viewed their staff, they tended to rate taller people as more effective.

There were correlations between actual performance and height in some jobs - such as face-to-face selling positions.

However, the correlation between height and earnings rang true in other occupations such as computer programming, accounting, engineering and clerical work.

It was even more important than gender in defining how much one person earned in relation to another.

Growth hormone

Professor Judge said that the reasons behind the prejudice could be psychological on the part of the employee, or even be rooted in evolution.

He said: "When humans evolved as a species and still lived in the jungles or the plain, they ascribed leader-like qualities to tall people because they thought they would be better able to protect them.

"Although that was thousands of years ago, evolutionary psychologists would argue that some of those old patterns still operate in our perceptions today."

Professor Sara Rynes, from the University of Iowa, said that the bias was "difficult to eradicate".

She added: "I recently read that because of the widely-perceived advantages of height, an increasing number of parents are seeking growth-hormone therapy for their shorter-than-average children."