He says his team's research is influenced by questions in evolutionary biology about why people and groups use costly punishment.

VOA: special.2009.03.03

Why,he asks? Because,he says, advertising is everywhere -- online,on television, even outside on buses and billboards.

VOA: special.2010.06.04

We asked competitor Chuck Mung from Portland,Oregon why he thinks air guitar is so popular.

VOA: special.2009.08.14

"But," he went on, "there is no reason in the world why Negroes should not have all the natural rights listed in the Declaration of Independence.

VOA: special.2009.06.11

He said that is why North Korea now faces stronger sanctions.

VOA: special.2010.01.30

But that is not why he wants to help people.

VOA: special.2009.07.31

"If you get a doctor who is away in the village and has come across a case he or she thinks is beyond him or her, why cannot that doctor be able to link up easily with a senior doctor in Korle Bu to get advice on it?

VOA: special.2009.06.17

He says that is why the president has proposed adding 25,000 police personnel to each of the country's four provinces.

VOA: standard.2009.03.30

Why he lied I don't know,". This is the last case before the U.N.Special Court for Sierra Leone.

VOA: standard.2009.11.10

So why is he showing up now? Peter DeShazo of the Center for Strategic and International Studies in Washington thinks he knows why.

VOA: standard.2010.07.13

"And that I believe is one of the reasons why he decided to resort to surgical interventions.

VOA: standard.2009.06.28

He said that he is living a dream, so why would he give it up now?

VOA: standard.2010.02.28

He says that is why the people started this protest, no one told them to do so, they did it themselves, and they took power without help of the political opposition.

VOA: standard.2010.04.08

"That is why he removed me from this position.

VOA: standard.2009.11.08