Meaning: 'Emphasis' refers to special importance or significance placed on something, in this case, scientific thinking in psychology.

Wrong options:

• emphasizing: This is a gerund and does not fit as it would require a different grammatical structure, such as 'the act of emphasizing.'
• emphasize: This is a verb form that does not fit grammatically in the context of the sentence, which requires a noun.
• emphasized: This is the past tense of the verb and does not fit as it does not serve as a noun in this context.

Correct answer: explore

Explanation: The verb 'explore' fits grammatically as it is in the present tense, matching the plural subject 'studies.' Contextually, it indicates the action of investigating different aspects of human nature, which aligns with the scientific studies mentioned.

Meaning: 'Explore' means to investigate or examine something in detail, in this case, various aspects of human nature.

Wrong options:

• demonstrate: This verb implies showing or proving something, which does not fit the context of investigating different aspects.
• pursuit: This noun does not fit grammatically as it does not convey an action related to studies; it refers to the act of chasing or seeking.
• include: This verb suggests adding something to a group, which does not align with the context of actively investigating.

Correct answer: senses

Explanation: The plural noun 'senses' fits grammatically as it refers to the five faculties (touch, taste, smell, sight, and hearing) that people use to perceive the world. Contextually, it aligns with the discussion of how people experience their environment.

Meaning: 'Senses' refers to the physiological capacities of humans to perceive stimuli, such as sight and hearing.

Wrong options:

• feelings: This noun refers to emotional states and does not fit as it does not relate to the physical faculties used to perceive the world.
• consciousness: This noun refers to the state of being aware of and able to think, which does not fit the context of physical perception.
• sensing: This gerund does not fit grammatically as it does not serve as a noun in this context.

Correct answer: investigations

Explanation: The noun 'investigations' fits grammatically as it serves as the subject of the clause, indicating the studies conducted in psychology. Contextually, it aligns with the scientific nature of the studies being discussed.

Meaning: 'Investigations' refers to systematic inquiries or examinations into a subject, in this case, human nature.

Wrong options:

• results: This noun refers to outcomes or conclusions of studies, which does not fit as it does not describe the process of studying.
• findings: This noun refers to the conclusions drawn from studies, which does not fit as it does not describe the act of studying itself.
• inventions: This noun refers to creations or innovations, which does not fit the context of scientific studies in psychology.

Correct answer: understanding

Explanation: The noun 'understanding' fits grammatically as it serves as the object of the preposition 'of,' indicating what the investigations contribute to. Contextually, it aligns with the goal of psychology to provide insight into human nature.

Meaning: 'Understanding' refers to the ability to comprehend or grasp the meaning of something, in this case, human nature.

Wrong options:

• estimation: This noun refers to an approximate calculation or judgment, which does not fit the context of gaining insight into human nature.
• appreciation: This noun refers to recognition and enjoyment of the good qualities of someone or something, which does not fit the context of knowledge in psychology.
• idea: This noun refers to a thought or suggestion, which does not convey the depth of comprehension implied by 'understanding.'

Correct answer: use

Explanation: The verb 'use' fits grammatically as it is in the base form, matching the subject 'people' and indicating an action they can take with their knowledge. Contextually, it suggests applying psychological knowledge in practical situations.

Meaning: 'Use' means to employ something for a purpose, in this case, applying psychological knowledge in various areas.

Wrong options:

• learn: This verb implies acquiring knowledge, which does not fit as it does not indicate application of knowledge already acquired.
• study: This verb suggests the act of learning or examining something, which does not fit the context of applying knowledge.
• find: This verb implies discovering something, which does not align with the context of utilizing knowledge.