Sentence:  The ability to look at both sides of a coin before giving a verdict can be both a curse and a blessing. ... This "<WSD>Janus</WSD> effect" (my term) is a curse when it blocks a time sensitive judgment response, or a decision waiting to be made before long. ... Friendships, sibling harmony, good relationship with associates at work, and especially marriages, could be great and positive recipients of the good that such a <WSD>Janus</WSD> effect could bring on. 
Meaning of the word marked with <WSD> tags:  (faces (such as animals with diprosopus) or aspects; or made of two different materials; or having a two-way action.)