Science Interviews

Guessing Physical Attributes from Someone's Voice

This week we're going to be replicating a famous experiment (Krauss et al., Journal of Experimental Social Psychology (2002) 38: 618 - 625) that examines people's ability to judge someone's height and age by listening to their voice. We've got our Kitchen Science guru Derek here in the studio, and we want you to let us know how old and how tall he is. We'll reveal the answer at the end of the show....

Chris - We've had quite a few guesses tonight about what you look like and how tall you are. It's ranged from age 45, 48, 32, 35 and people estimating between 5 foot 11 inches and 5 foot 6 inches.

Derek - Well I've been quite nervous to hear it all, but I can now reveal the details of my height and my age. I am in fact younger than all of those and younger, I think, than anyone guessed. I'm actually 27, I'm a fresh-faced young lad and I'm 5 foot 10, and I think someone did actually get very close to that.

Chris - Yes, Helen in Norwich thought that you were 28 and put your height at 5 foot 10.

Derek - Yes, so basically you're one year out. That's fantastic. So what I'm wondering is, do you know me, because everyone else was miles out.

Chris - Well now that we've done that, we've found that people can get it right but on average there was a bit of a skew in our study. When the scientists did this experiment, did they find largely this result or did it work?

Derek - It did actually work. The thing is that I work in radio and my voice is chosen because it's maybe deeper than other people's voices. Maybe that's affected people's thinking about how old I am. But when the scientists did this down at Columbia University in New York, they found that if they showed someone a picture or played someone a voice of the same person, if people made a judgement about age and height from the voice, it was practically as good as them using the picture. So using a visual cue was just about the same as using the speech cue.

Chris - So what this suggests is that when someone makes threatening phone calls or says that there's going to be a bomb somewhere, instead of hiring very expensive experts to come and analyse voices, you could do it cheaper by asking the radio listeners what they think of the voice.

Derek - Absolutely. Of course if I choose to do something like that then they're never going to guess who I am, which is perfect.

Chris - Yes, so if you ever need a new career Derek, you can be a threatening phone call maker or something.

Derek - Not something I'd really call a career but a one off maybe.

August 2006