Currently, the type of biometric methods that are being used are physical. The behavioral method identification in Aadhaar is possible with biometrics technology as per available information.
Aadhaar is currently doing the identification obtained with the iris and fingerprint, both already a very reliable method of authentication proven as per science and tech experts.
The discussions about farm workers having unreadable finger prints is hot in America and the feasible options are the readings of the iris.
The data is specific and unique to each individual and so these are sure ways to make sure the originator is the person accessing the identity. Indian UId Aadhaar project has many complaints about the simple identity objects but people are not aware of biometrics rather at the moment it is beyond their reach. All of the scanning requires that the person is stationed in one area and is scanned with a hand held or step to a scanning device, but thanks to the fears established through terrorism, scanning at a distance is more a reality than before.
The process can read iris with facial recognition from up to 12 meters away. Whether Aadhaar will be using this or not has yet to be seen, but the Department of Defense (DoD) has already granted the team developing the technology and have set a goal to have a functioning prototype by 2014.