When ethnic groups intermarry, it is likely to result in cognitive ben

According to my understanding, the subject The intermarriage of ethnic groups is singular, it is also evident from the fact that verb is has been used in the first half. But in the second half of the sentence, according to option B, the same subject took plural verb have.

Please explain.

Thank you.

Hi,

Here HAVE does not refer to plural subject...
Whenever you are using MAY, it will contain base/plural form of VERB..

Examples..
He may go to market.... otherwise - He goes to market.
He may have the book... otherwise - He has the book.
He might/may have gone for the movie... otherwise - he has gone for the movie.

When ethnic groups intermarry, it is likely to result in cognitive benefits; indeed, perhaps already having contributed to the Flynn effect, which has been the worldwide rise in average IQ score by as much as three points per decade over most of the past century.

A) When ethnic groups intermarry, it is likely to result in cognitive benefits; indeed, perhaps having contributed to the Flynn effect, which has been : Dangling modifier. Not sure to what it is referring to.

B) The intermarriage of ethnic groups is likely to result in cognitive benefits and may indeed have contributed to the Flynn effect,

C) When ethnic groups intermarry, they are likely to result in cognitive benefits and may indeed have contributed to the Flynn effect, the name given to : Change in meaning + "the name given" is wordy
D) Ethnic groups that intermarry will likely result in cognitive benefits; indeed, possibly having contributed to the Flynn effect, : Same as A

E) The intermarriage of ethnic groups, likely to result in cognitive benefits, indeed have possibly contributed to the Flynn effect, the name given to : Same as A

When ethnic groups intermarry, it is likely to result in cognitive benefits; indeed, perhaps already having contributed to the Flynn effect, which has been the worldwide rise in average IQ score by as much as three points per decade over most of the past century.

(A) When ethnic groups intermarry, it is likely to result in cognitive benefits; indeed, perhaps having contributed to the Flynn effect, which has been (It has no clear antecedent and the clause after semicolon is not a independent clause which we require )

(B) The intermarriage of ethnic groups is likely to result in cognitive benefits and may indeed have contributed to the Flynn effect, (Correct)

(C) When ethnic groups intermarry, they are likely to result in cognitive benefits and may indeed have contributed to the Flynn effect, the name given to (Wrong meaning)

(D) Ethnic groups that intermarry will likely result in cognitive benefits; indeed, possibly having contributed to the Flynn effect, (No independent clause and wrong meaning in Ethnic groups that intermarry will likely.... )

(E) The intermarriage of ethnic groups, likely to result in cognitive benefits, indeed have possibly contributed to the Flynn effect, the name given to (S-V agreement and wrong modifier likely to result is modifying ethnic groups ,which is wrong )

This sentence describes a likely positive consequence of the intermarriage of ethnic groups: specifically, such intermarriage is likely to produce cognitive benefits for the resulting offspring. The sentence then goes on to speculate that the intermarriage of ethnic groups may also be one of the causes of the Flynn effect, the recent global increase in average IQ. The correct answer will convey this Meaning.

(A) The pronoun it has no antecedent. In context, that pronoun is intended to refer to the intermarriage of ethnic groups, but the noun intermarriage is not present in the sentence. The portion of the sentence following the semicolon is not a complete sentence—it contains neither a subject nor a verb—and so the sentence as a whole is a fragment.

(B) CORRECT. The sentence properly uses a compound verb construction (is likely … and may) to describe two possible facts about the kind of intermarriage described. The noun modifier the worldwide rise is properly used to explain what the Flynn effect is. Finally, the sentence is accurate in meaning: the intermarriage of ethnic groups, not the ethnic groups themselves, is likely to result in cognitive benefits.

(C) This sentence illogically states that the ethnic groups themselves, rather than the intermarriage between them, are likely to result in cognitive benefits. The combination of a cause in the present tense (are likely to) and its effect in the present perfect (have contributed) is illogical, implying that the effect somehow preceded the cause. Finally, the phenomenon may have contributed to the Flynn effect itself; the phenomenon did not contribute to the name given to the effect.

(D) This sentence illogically states that the ethnic groups themselves, rather than the intermarriage between them, will likely result in cognitive benefits. The portion of the sentence following the semicolon is not a complete sentence—it contains neither a subject nor a verb—and so the sentence as a whole is a fragment.

(E) The singular subject the intermarriage does not agree with the plural verb have contributed. Finally, the phenomenon [has] possibly contributed to the Flynn effect itself; the phenomenon did not contribute to the name given to the effect.

in A] is 'IT' working as a placeholder.

also, I often get confused with the stylistic modifier 'having contributed' i.e of the type - ''ing+ed verbal''.Could you please share examples when the usage is correct and when not?

Hello Anshul1223333,

We hope this finds you well.

To answer your query, yes; in Option A, "it" is a placeholder pronoun.

Further, the "present participle ("verb+ing") + past participle" construction is an adverbial modifier; in modifying a primary action, it conveys that the doer of the action completed the action referred to by the past participle before the primary action.

We hope this helps.
All the best!
Experts' Global Team