Question: who created the idea that reciprocity is important for maintaining relationships
[{'answer': 'Hammurabi', 'provenance': [{'wikipedia_id': '1213355', 'title': 'Reciprocity (social psychology)', 'start_paragraph_id': 5, 'start_character': 45, 'end_paragraph_id': 5, 'end_character': 54, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '1213355', 'title': 'Reciprocity (social psychology)', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 513, 'bleu_score': 0.9382880328341491, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7612698406770399698}, 'section': 'Section::::History.\n'}]}]