So You Want to Be A Scientist 2012 Experiments - Stripey Clothes

Original Idea

Val Watham

Name: Val Watham

Occupation: Organisational Consultant

Age: 53

Location: Berkshire

Question: What effect do horizontal and vertical stripes have on our perception of someone's size?


Traditionally, it's been thought that vertical stripes make you look taller and thinner.

However, a study by Dr Peter Thompson from the University of York, revealed that horizontal stripes create a visual illusion making shapes appear taller and narrower. This is called the Helmholtz illusion, named after Prussian physiologist Hermann von Helmholtz.

Helmholtz illusion

But Peter Thompson's study on stripey clothes was only done using 2D line drawings. So Val is aiming, with Peter's help, to update the experiment using 3D videos of real people wearing dresses and shirts.


Val found that vertical stripes make you look taller, horizontal hoops will mean you appear wider. But black clothes are the most slimming of all.

These results were statistically significant (p

Val's findings contradict the research of her mentor, Dr Peter Thompson, who found that horizontal stripes made you look taller and thinner than verticals.

Dr Thompson is planning to follow up Val's study with an experiment on stripey tights, to see if he can repeat her results.

Producing The Clothes

UCA Fashion Shoot

Val worked with first year fashion design students at the University of the Creative Arts in Rochester to make the outfits to use in her test.

The students designed and made up fifteen dresses and shirts in various sizes, featuring horizontal and vertical stripes, as well as a plain black alternative.

During a fashion shoot, Val recorded the students modelling each outfit and the videos were used to produce an interactive experiment.

Data Gathering

The team took their experiment to Edinburgh Science Festival from 13-15 April 2012, as part of the BBC Bang Goes the Theory LIVE interactive tent.

Over 500 visitors watched and rated the videos to say how tall and wide the models appeared in each outfit.

Follow Val's Research Diary on Facebook

To talk to Val about her experiment, click 'like' to follow her Facebook research diary

Scientific Mentor

Dr Peter Thompson

Dr Peter Thompson
Senior Lecturer in Psychology
University of York
Speciality: visual perception

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