Valmiki Ramayana Kishkindha Kanda Sarga 24 Shloka 12

अनेन by him, भ्रातृत्वम् brotherliness आर्यभावश्च feeling of respect, धर्मश्च feeling of duty, रक्षितः protected, मया by me, क्रोधश्च anger, कामश्च passion, कपित्वं च monkey nature, प्रदिर्शितम् is exhibited.

'Thus while nobility, a feeling of respect,brotherliness and duty was shown to me by my brother, I exhibited wrath, passion and frivolity, the nature of the monkey.