It is a science because it aims to explain the greatest number of facts with the fewest number of assumptions , its hypotheses are supposed to be falsifiable by empirical tests , and its theories are lawfully connected to other sciences , particularly biology 它是一门科学，因为心理学的目标在以最少的假设解释最多的事实，心理学的假设容许被实征检验推翻，心理学的理论合理地衔接其他科学，特别是生物学。
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The traditional means , such as key , password , cryptogram , id card and even ic card , have fallen behind the needs of economic activity and social security . this is because that they would be forgeable , falsifiable , stolen or decodable 传统的个人身份鉴别手段如钥匙、口令、密码、身份证件，甚至ic卡等识别方式，由于它们具有可假冒、可伪造、可盗用、可破译的弱点，已不能完全满足现代社会经济活动和社会安全防范的需要。
