"Mark Harris, of the London-based Control Risks Group, a business consultancy operation, said both the hostages and the hostage-takers will be feeling the psychological strain of their situation.
Harris told CNN: "The hostages will be going through shock, disbelief, and denial at what is taking place and they really will be very, very confused about what has happened to them. I think this will then move, probably, into feelings of that this whole thing is unreal.
"It is a very dangerous situation and those outside, their families and loved-ones, will also be going through those types of emotions as well."
As for the hostage-takers: "Obviously, as soon as they went in and as soon as they took the action they did they are going to be at risk themselves. In order to take those type of actions they are going to be very excited -- the adrenalin will be going -- and they would have been extremely nervous during the first hours of the operation.
"They will then settle down a bit, but as the negotiations draw out and they see what their situation becomes then that can create strains within the group and also conflict among leaders."
He said the size of the hostage group -- believed to be up to 700 people -- would also plays its part.
He said: "Certainly, from my knowledge, this is one of the largest (hostage situations) we have seen in a long time. I think the main thing about it is that depending on how many actual hostage takers there are, they are going to have to look at how they secure everybody and they may well want to start looking at the idea of bringing down the size of the (hostage group).
"Obviously, it's going to take up a lot of resources, a lot of water, food and care. If you are not looking after the hostages then they are going to become a problem and its another factor that will have to be taken into consideration."
Studies have been made of the psychological impact of been taken on hostage while many who have been held hostage, such as Britons Terry Waite and John McCarthy -- who were held in the Middle East for years -- have written of their ordeal.
But the foundations for much of the existing research is based on the so-called 'Stockholm Syndrome,' arising from an incident in Sweden in 1973 when a gunman held four bank employees hostage in a small vault for over five days.
Later interviews with the hostages yielded surprising results -- results that have been confirmed in numerous other "hostage situations" in the years that followed.
The captives displayed a strange association with their captor, identifying with him while fearing those who sought to end their captivity.
At least at first this is a defensive mechanism, based on the idea that the captor will not hurt the captive if he is cooperative and even positively supportive. The captive seeks to win the favour of the captor in an almost childlike way.
The captive often realises that action taken by his would-be rescuers is very likely to hurt him instead of obtaining his release.
Attempts at rescue may turn a presently tolerable situation into a lethal one.
Particularly in political or ideological situations, longer captivity also allows the captive to become familiar with the captor's point of view and the history of his grievances against authority.
He may, in some situations, come to believe that the captor's position is just.