Biometrics is a unique art that exists within a person and allows it to be used to differentiate between one another. These biometrics can be divided into two categories namely behaviour and physical such as face, fingerprint, hand, voice and gait. There are previous studies which examine the personal's characteristic or personality as gender, age, cultural, weight, height, colour of hair etc. This personal's characteristic or personality also known as soft biometric. Several previous studies have shown that the use of soft biometric element (one or combination of elements) in the process of identifying individuals can improve the performance of individual recognition. This paper will elaborate and concludes past studies related to the use of soft biometric elements in KD. Several soft biometric elements applied in various methods of recognition on previous studies have been listed and the results of the studies are compared.
